Fair Value Disclosures [Abstract]
Fair Value Measurements, Recurring and Nonrecurring [Table]
Fair Value Measurements, Recurring and Nonrecurring [Table]
Measurement Frequency [Axis]
Measurement Frequency [Axis]
Fair Value, Measurement Frequency [Domain]
Fair Value, Measurement Frequency [Domain]
Recurring
Fair Value, Measurements, Recurring [Member]
Fair Value, Hierarchy [Axis]
Fair Value, Hierarchy [Axis]
Fair Value Hierarchy [Domain]
Fair Value Hierarchy [Domain]
Level 1
Fair Value, Inputs, Level 1 [Member]
Level 2
Fair Value, Inputs, Level 2 [Member]
Level 3
Fair Value, Inputs, Level 3 [Member]
Hedging Designation [Axis]
Hedging Designation [Axis]
Hedging Designation [Domain]
Hedging Designation [Domain]
Not designated as hedging instrument
Not Designated as Hedging Instrument [Member]
Designated as hedging instrument
Designated as Hedging Instrument [Member]
Derivative Instrument [Axis]
Derivative Instrument [Axis]
Derivative Contract [Domain]
Derivative Contract [Domain]
Energy contracts subject to regulatory deferral
Energy Related Derivatives Subject to Regulatory Deferral [Member]
Energy Related Derivatives Subject to Regulatory Deferral [Member]
Energy contracts not subject to regulatory deferral
Energy Related Derivatives Not Subject to Regulatory Deferral [Member]
Energy Related Derivatives Not Subject to Regulatory Deferral [Member]
Interest rate swaps
Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets
Assets, Fair Value Disclosure [Abstract]
Derivative asset
Derivative Asset
Other investments
Other Investments, Fair Value Disclosure
Other Investments, Fair Value Disclosure
Total gross assets
Assets, Fair Value Disclosure
Less: Counterparty netting not offset on the balance sheet
Derivative Asset, Not Offset, Policy Election Deduction
Total net assets
Assets, Fair Value Disclosure, Net of Amount Not Offset Against Collateral
Assets, Fair Value Disclosure, Net of Amount Not Offset Against Collateral
Liabilities
Liabilities, Fair Value Disclosure [Abstract]
Derivative liability
Derivative Liability
Total gross liabilities
Financial and Nonfinancial Liabilities, Fair Value Disclosure
Less: Counterparty netting not offset on the balance sheet
Derivative Liability, Not Offset, Policy Election Deduction
Total net liabilities
Liabilities, Fair Value Disclosure, Net of Amount Not Offset Against Collateral
Liabilities, Fair Value Disclosure, Net of Amount Not Offset Against Collateral
Regulated Operations [Abstract]
Schedule of Regulatory Assets
Schedule of Regulatory Assets [Table Text Block]
Schedule of Regulatory Liabilities
Schedule of Regulatory Liabilities [Table Text Block]
Equity [Abstract]
Schedule of Common Shares Issued During the Year
Schedule of Common Stock Outstanding Roll Forward [Table Text Block]
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments [Table]
Schedule of Long-term Debt Instruments [Table]
Long-term Debt, Type [Axis]
Long-term Debt, Type [Axis]
Long-term Debt, Type [Domain]
Long-term Debt, Type [Domain]
Credit facility
Line of Credit [Member]
Debt Instrument [Axis]
Debt Instrument [Axis]
Debt Instrument, Name [Domain]
Debt Instrument, Name [Domain]
Long-term credit facility borrowings
Long-term Credit Facility Borrowings [Member]
Long-term Credit Facility Borrowings [Member]
Debt Instrument [Line Items]
Debt Instrument [Line Items]
Long-term debt, excluding credit facility borrowings
Long-Term Debt Excluding Credit Facilities
Long-Term Debt Excluding Credit Facilities
Long-term debt
Long-term Debt, Gross
Less: Deferred financing costs and debt discounts
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net
Less: Current installments of long-term debt
Long-term Debt, Current Maturities
Long-term debt less current portion and deferred financing costs and debt discounts
Long-term Debt, Excluding Current Maturities
Accounting Policies [Abstract]
Summary of Significant Accounting Policies
Significant Accounting Policies [Text Block]
Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition [Table]
Schedule of Business Acquisitions, by Acquisition [Table]
Business Acquisition [Axis]
Business Acquisition [Axis]
Business Acquisition, Acquiree [Domain]
Business Acquisition, Acquiree [Domain]
Aitken Creek Gas Storage ULC
Aitken Creek Gas Storage ULC [Member]
Aitken Creek Gas Storage ULC
Business Acquisition [Line Items]
Business Acquisition [Line Items]
Cash purchase price, plus the cost of working gas inventory
Payments to Acquire Businesses, Net of Cash Acquired
Deposit on acquisition paid
Other Payments to Acquire Businesses
Goodwill
Goodwill
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based Compensation Plans
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]
Business Acquisitions
Business Combination Disclosure [Text Block]
Statement of Stockholders' Equity [Abstract]
Statement [Table]
Statement [Table]
Equity Components [Axis]
Equity Components [Axis]
Equity Component [Domain]
Equity Component [Domain]
Common Shares (Note 7)
Common Stock [Member]
Preference Shares
Preferred Stock [Member]
Additional Paid-In Capital
Additional Paid-in Capital [Member]
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent [Member]
Retained Earnings
Retained Earnings [Member]
Non-Controlling Interests
Noncontrolling Interest [Member]
Statement [Line Items]
Statement [Line Items]
Increase (Decrease) in Equity [Roll Forward]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest
Net earnings
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest
Other comprehensive loss
Other Comprehensive Income (Loss), Net of Tax
Common share issues
Stock Issued During Period, Value, New Issues
Stock-based compensation
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition
Advances from non-controlling interests
Noncontrolling Interest, Increases From Advances From Noncontrolling Interests
Noncontrolling Interest, Increases From Advances From Noncontrolling Interests
Foreign currency translation impacts
Noncontrolling Interest, Foreign Currency Translation Adjustments
Noncontrolling Interest, Foreign Currency Translation Adjustments
Subsidiary dividends paid to non-controlling interests
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders
Dividends declared on common shares
Dividends, Common Stock
Dividends declared on preference shares
Dividends, Preferred Stock
Adoption of new accounting policy
Cumulative Effect of New Accounting Principle in Period of Adoption
Balance, end of period
Fair Value Measurements and Financial Instruments
Derivatives and Fair Value [Text Block]
Document and Entity Information [Abstract]
Document and Entity Information [Abstract]
Entity Registrant Name
Entity Registrant Name
Entity Central Index Key
Entity Central Index Key
Current Fiscal Year End Date
Current Fiscal Year End Date
Document Type
Document Type
Document Period End Date
Document Period End Date
Document Fiscal Year Focus
Document Fiscal Year Focus
Document Fiscal Period Focus
Document Fiscal Period Focus
Amendment Flag
Amendment Flag
Entity Common Stock, Shares Outstanding
Entity Common Stock, Shares Outstanding
Income Statement [Abstract]
Revenue
Revenues
Expenses
Operating Costs and Expenses [Abstract]
Energy supply costs
Cost of Services, Energy Services
Operating
Operating Expenses
Depreciation and amortization
Depreciation, Depletion and Amortization
Total expenses
Costs and Expenses
Operating income (loss)
Operating Income (Loss)
Other income, net (Note 10)
Nonoperating Income (Expense)
Finance charges (Note 11)
Interest Expense
Income tax expense
Income Tax Expense (Benefit)
Net earnings (loss)
Net earnings attributable to:
Income Amounts Attributable to Parent, Disclosures [Abstract]
Non-controlling interests
Net Income (Loss) Attributable to Noncontrolling Interest
Preference equity shareholders
Preferred Stock Dividends and Other Adjustments
Common equity shareholders
Net Income (Loss) Available to Common Stockholders, Basic
Net earnings (loss)
Earnings per common share (Note 12)
Earnings Per Share [Abstract]
Basic (CAD per share)
Earnings Per Share, Basic
Diluted (CAD per share)
Earnings Per Share, Diluted
Compensation and Retirement Disclosure [Abstract]
Employee Future Benefits
Pension and Other Postretirement Benefits Disclosure [Text Block]
Risks and Uncertainties [Abstract]
Financial Risk Management
Concentration Risk Disclosure [Text Block]
Long-Term Debt
Long-term Debt [Text Block]
Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table]
Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table]
Award Type [Axis]
Award Type [Axis]
Equity Award [Domain]
Equity Award [Domain]
DSUs
Directors’ Deferred Share Unit [Member]
Directors’ Deferred Share Unit [Member]
Title of Individual [Axis]
Title of Individual [Axis]
Relationship to Entity [Domain]
Relationship to Entity [Domain]
Director
Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (shares)
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted
Unit with underlying value equivalent to common shares
Share-based Compensation Arrangement by Share-based Payment Award, Other than Options, Conversion Equivalent Ratio
Share-based Compensation Arrangement by Share-based Payment Award, Other than Options, Conversion Equivalent Ratio
Earnings Per Common Share
Earnings Per Share [Text Block]
ITC
ITC Holdings Corp. [Member]
ITC Holdings Corp. [Member]
Investment, Name [Axis]
Investment, Name [Axis]
Investment, Name [Domain]
Investment, Name [Domain]
Unsecured
Unsecured Debt [Member]
US Shareholder Note
US Shareholder Note [Member]
US Shareholder Note [Member]
Credit Facility [Axis]
Credit Facility [Axis]
Credit Facility [Domain]
Credit Facility [Domain]
Bridge loan
Bridge Loan [Member]
Short-term Debt, Type [Axis]
Short-term Debt, Type [Axis]
Short-term Debt, Type [Domain]
Short-term Debt, Type [Domain]
Income Statement Location [Axis]
Income Statement Location [Axis]
Income Statement Location [Domain]
Income Statement Location [Domain]
Operating expenses
Operating Expense [Member]
Finance charges
Interest Expense [Member]
Legal Entity [Axis]
Legal Entity [Axis]
Entity [Domain]
Entity [Domain]
Aggregate purchase price
Business Combination, Consideration Transferred
Consolidated indebtedness at fair value acquired
Business Combination, Consideration Transferred, Liabilities Incurred
Noncontrolling ownership (percent)
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners
Cash paid per share (USD per share)
Business Combination, Consideration Cash Per Common Share
Business Combination, Consideration Cash Per Common Share
Entity shares issued per acquiree share
Business Combination, Consideration Stock Per Common Share
Business Combination, Consideration Stock Per Common Share
Cash and share consideration given
Business Combination, Consideration Transferred, Excluding Liabilities Incurred
Business Combination, Consideration Transferred, Excluding Liabilities Incurred
Payment for ownership
Payments to Acquire Businesses, Gross
Face value
Debt Instrument, Face Amount
Advances from non-controlling interests
Proceeds from Noncontrolling Interests
Drawings from non-revolving term senior unsecured equity bridge credit facility
Proceeds from Lines of Credit
Shares issued per share purchased
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares
Share consideration
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable
Closing share price (CAD per share)
Share Price
Foreign exchange rate (CAD per USD)
Foreign Currency Exchange Rate, Translation
Acquisition-related expenses
Business Combination, Acquisition Related Costs
Acquisition-related expenses, net of tax
Business Combination, Acquisition Related Costs, Net of Tax
Business Combination, Acquisition Related Costs, Net of Tax
Accelerated vesting of the stock-based compensation awards
Business Combination, Separately Recognized Transactions, Expenses and Losses Recognized
Segment Reporting [Abstract]
Schedule of Related Party Transactions, by Related Party [Table]
Schedule of Related Party Transactions, by Related Party [Table]
Waneta Expansion
Waneta Expansion Limited Partnership [Member]
Waneta Expansion Limited Partnership [Member]
Belize Electric Company
Belize Electric Company Limited [Member]
Belize Electric Company Limited [Member]
Aitken Creek
Aitken Creek [Member]
Aitken Creek [Member]
Related Party [Axis]
Related Party [Axis]
Related Party [Domain]
Related Party [Domain]
Equity Method Investee
Equity Method Investee [Member]
Belize Electricity
Belize Electricity Limited [Member]
Belize Electricity Limited [Member]
Related Party Transaction [Line Items]
Related Party Transaction [Line Items]
Intercompany revenue recognized
Intercompany Revenue Recognized
Intercompany Revenue Recognized
Due from related party
Due from Related Parties, Current
Equity investment ownership (percent)
Equity Method Investment, Ownership Percentage
Common Shares
Stockholders' Equity Note Disclosure [Text Block]
Caribbean Utilities
Caribbean Utilities Company, Ltd. [Member]
Caribbean Utilities Company, Ltd. [Member]
Newfoundland Power
Newfoundland Power Inc. [Member]
Newfoundland Power Inc. [Member]
Secured
Secured Debt [Member]
1 year variable rate term loan
One Year Floating Rate Unsecured Term Loan Credit Agreement [Member]
One Year Floating Rate Unsecured Term Loan Credit Agreement [Member]
2 year variable rate term loan
Two Year Floating Rate Unsecured Term Loan Credit Agreement [Member]
Two Year Floating Rate Unsecured Term Loan Credit Agreement [Member]
30 year 4.16% secured notes
Thirty Year Four Point One Six Percent Secured Notes [Member]
Thirty Year Four Point One Six Percent Secured Notes [Member]
Unsecured notes in a dual tranche offering
Unsecured Notes, Dual Tranche Offering [Member]
Unsecured Notes, Dual Tranche Offering [Member]
15 year 3.90% unsecured notes
Fifteen Year Three Point Nine Percent Unsecured Notes [Member]
Fifteen Year Three Point Nine Percent Unsecured Notes [Member]
30 year 4.64% unsecured notes
Thirty Year Four Point Six Four Percent Unsecured Notes [Member]
Thirty Year Four Point Six Four Percent Unsecured Notes [Member]
40 year 3.82% first mortgage sinking fund bonds
Forty Year Three Point Eight Two Percent First Mortgage Sinking Fund Bonds [Member]
Forty Year Three Point Eight Two Percent First Mortgage Sinking Fund Bonds [Member]
Variable Rate [Axis]
Variable Rate [Axis]
Variable Rate [Domain]
Variable Rate [Domain]
LIBOR
London Interbank Offered Rate (LIBOR) [Member]
Debt term
Debt Instrument, Term
Variable rate (percent)
Debt Instrument, Basis Spread on Variable Rate
Term loan credit agreements
Stated interest rate (percent)
Debt Instrument, Interest Rate, Stated Percentage
Accounting Changes and Error Corrections [Abstract]
Future Accounting Pronouncements
Description of New Accounting Pronouncements Not yet Adopted [Text Block]
Supplemental Cash Flow Elements [Abstract]
Supplementary Information to Consolidated Statements of Cash Flows
Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]
Schedule of Regulatory Assets [Table]
Schedule of Regulatory Assets [Table]
Regulatory Asset [Axis]
Regulatory Asset [Axis]
Regulatory Asset [Domain]
Regulatory Asset [Domain]
Deferred income taxes
Deferred Income Tax Charge [Member]
Employee future benefits
Pension and Other Postretirement Plans Costs [Member]
Deferred energy management costs
Deferred Project Costs [Member]
Rate stabilization accounts
Rate Stabilization Accounts [Member]
Rate Stabilization Accounts [Member]
Deferred lease costs
Deferred Lease Costs [Member]
Deferred Lease Costs [Member]
Deferred operating overhead costs
Deferred Operating Overhead Cost [Member]
Deferred Operating Overhead Cost [Member]
Manufactured gas plant site remediation deferral
Environmental Restoration Costs [Member]
Navajo retirement costs
Retirement Costs [Member]
Retirement Costs [Member]
Natural gas for transportation incentives
Natural Gas Transition Cost [Member]
Other
Other Regulatory Assets (Liabilities) [Member]
Regulatory Assets [Line Items]
Regulatory Assets [Line Items]
Total regulatory assets
Regulatory Assets
Less: current portion
Regulatory Assets, Current
Long-term regulatory assets
Regulatory Assets, Noncurrent
Reclassification of capital assets to regulatory assets
Reclassification from Capital Assets to Regulatory Assets
Reclassification from Capital Assets to Regulatory Assets
Schedule of Regulatory Liabilities [Table]
Schedule of Regulatory Liabilities [Table]
Regulatory Liability [Axis]
Regulatory Liability [Axis]
Regulatory Liability [Domain]
Regulatory Liability [Domain]
Non-asset retirement obligation removal cost provision
Removal Costs [Member]
Rate stabilization accounts
Return on equity refund liability
Estimated Return on Equity Refund, Initial and Second Refund Period [Member]
Estimated Return on Equity Refund, Initial and Second Refund Period [Member]
Energy efficiency liability
Energy Efficiency Liability [Member]
Energy Efficiency Liability [Member]
Electric and gas moderator account
Electric and Gas Moderator Account [Member]
Electric and Gas Moderator Account [Member]
Renewable energy surcharge
Renewable Energy Program [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities [Line Items]
Total regulatory liabilities
Regulatory Liabilities
Less: current portion
Regulatory Liability, Current
Long-term regulatory liabilities
Regulatory Liability, Noncurrent
Commitments and Contingencies Disclosure [Abstract]
Site Contingency [Table]
Site Contingency [Table]
Loss Contingency Nature [Axis]
Loss Contingency Nature [Axis]
Loss Contingency, Nature [Domain]
Loss Contingency, Nature [Domain]
Asbestos Cases
Asbestos Issue [Member]
Claim related to pipeline rights
Claim Related to Pipeline Rights [Member]
Claim Related to Pipeline Rights [Member]
Central Hudson
Central Hudson Gas and Electric Corporation [Member]
Central Hudson Gas and Electric Corporation [Member]
FHI and Fortis
FHI and Fortis [Member]
FHI and Fortis [Member]
Site Contingency [Line Items]
Site Contingency [Line Items]
Total asbestos cases raised (number)
Loss Contingency, New Claims Filed, Number
Remaining asbestos cases (number)
Loss Contingency, Pending Claims, Number
Asbestos cases dismissed (number)
Loss Contingency, Claims Dismissed, Number
Asbestos cases settled (number)
Loss Contingency, Claims Settled, Number
Contingency accrual
Loss Contingency Accrual
Basis of Accounting
Basis of Accounting, Policy [Policy Text Block]
Use of Accounting Estimates
Use of Estimates, Policy [Policy Text Block]
Consolidation
Consolidation, Subsidiaries or Other Investments, Consolidated Entities, Policy [Policy Text Block]
New Accounting Policies
New Accounting Pronouncements, Policy [Policy Text Block]
Finance Charges
Debt Disclosure [Text Block]
RSUs
Restricted Stock Units (RSUs) [Member]
Granted (shares)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period
Award vesting period
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period
Concentration Risk [Table]
Concentration Risk [Table]
Concentration Risk Benchmark [Axis]
Concentration Risk Benchmark [Axis]
Concentration Risk Benchmark [Domain]
Concentration Risk Benchmark [Domain]
Revenue
Sales Revenue, Net [Member]
Customer [Axis]
Customer [Axis]
Customer [Domain]
Customer [Domain]
Three Customers
Three Customers [Member]
Three Customers [Member]
Concentration Risk Type [Axis]
Concentration Risk Type [Axis]
Concentration Risk Type [Domain]
Concentration Risk Type [Domain]
Customer Concentration Risk
Customer Concentration Risk [Member]
Credit risk exposure
Credit Concentration Risk [Member]
FortisAlberta
Fortis Alberta Inc. [Member]
Fortis Alberta Inc. [Member]
Concentration Risk [Line Items]
Concentration Risk [Line Items]
Concentration risk percentage
Concentration Risk, Percentage
Gross credit risk exposure
Concentration Risk, Credit Risk, Financial Instrument, Maximum Exposure
Retailer billings (over) (period)
Concentration Risk, Credit Risk, Financial Instrument, Term Of Credit Risk
Concentration Risk, Credit Risk, Financial Instrument, Term Of Credit Risk
Reduction in credit risk exposure due to deposit, bond, letter of credit, investment grade credit rating or other guarantee
Concentration Risk, Credit Risk, Financial Instrument, Maximum Exposure, Increase (Decrease), Due To Deposit Or Other Guarantee
Concentration Risk, Credit Risk, Financial Instrument, Maximum Exposure, Increase (Decrease), Due To Deposit Or Other Guarantee
Schedule of Segment Reporting Information, by Segment [Table]
Schedule of Segment Reporting Information, by Segment [Table]
Regulation Status [Axis]
Regulation Status [Axis]
Regulated and Unregulated Operation [Domain]
Regulated and Unregulated Operation [Domain]
REGULATED
Regulated Operation [Member]
NON-REGULATED
Unregulated Operation [Member]
Consolidation Items [Axis]
Consolidation Items [Axis]
Consolidation Items [Domain]
Consolidation Items [Domain]
Operating segments
Operating Segments [Member]
Inter-segment eliminations
Intersegment Eliminations [Member]
Geographical [Axis]
Geographical [Axis]
Geographical [Domain]
Geographical [Domain]
United States
UNITED STATES
Canada
CANADA
Caribbean
Caribbean [Member]
Caribbean [Member]
Segments [Axis]
Segments [Axis]
Segments [Domain]
Segments [Domain]
UNS Energy
UNS Energy Corporation [Member]
UNS Energy Corporation [Member]
FortisBC Energy
FortisBC Energy Inc. [Member]
FortisBC Energy Inc. [Member]
FortisBC Electric
FortisBC Inc. [Member]
FortisBC Inc. [Member]
Eastern Canadian
Eastern Canadian [Member]
Eastern Canadian [Member]
Caribbean Electric
Caribbean Electric [Member]
Caribbean Electric [Member]
Energy Infrastructure
Energy Infrastructure [Member]
Energy Infrastructure [Member]
Corporate and Other
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Segment Reporting Information [Line Items]
Operating expenses
Other income (expenses), net
Finance charges
Income tax expense (recovery)
Goodwill
Identifiable assets
Assets, Net (Excluding Goodwill)
Assets, Net (Excluding Goodwill)
Total assets
Assets
Gross capital expenditures
Payments to Acquire Productive Assets
Revenue generated from energy sales to retail and wholesale customers based on published tariff rates
Revenue Recognition, New Accounting Pronouncement, Tariff Revenue, Percentage
Revenue Recognition, New Accounting Pronouncement, Tariff Revenue, Percentage
Schedule of Credit Facilities
Schedule of Line of Credit Facilities [Table Text Block]
Commitments and Contingencies
Commitments and Contingencies Disclosure [Text Block]
Defined contribution plan cost recognized
Defined Contribution Plan, Cost Recognized
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Public Utilities General Disclosures [Table]
Public Utilities General Disclosures [Table]
Fortis Turks and Caicos
Fortis Turks and Caicos [Member]
Fortis Turks and Caicos [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, General Disclosures [Line Items]
Controlling ownership interest (percent)
Noncontrolling Interest, Ownership Percentage by Parent
Number of utilities
Public Utilities, Number Of Utilities
Public Utilities, Number Of Utilities
Schedule of Net Earnings to Common Shareholders
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
Supplementary Information to Condensed Consolidated Interim Statements of Cash Flows
Cash Flow, Supplemental Disclosures [Text Block]
Plan Name [Axis]
Plan Name [Axis]
Plan Name [Domain]
Plan Name [Domain]
2012 Plan
Stock Options, 2012 Plan [Member]
Stock Options, 2012 Plan [Member]
Options
Employee Stock Option [Member]
Dividend yield (%)
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate
Expected volatility (%)
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate
Risk-free interest rate (%)
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate
Weighted average expected life (years)
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term
Schedule of Stock Option Information
Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]
Line of Credit Facility [Table]
Line of Credit Facility [Table]
Commercial paper
Commercial Paper [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility [Line Items]
Total credit facilities
Line of Credit Facility, Maximum Borrowing Capacity
Credit facilities utilized:
Line of Credit Facility [Abstract]
Short-term borrowings
Short-term Debt
Long-term debt (Note 6)
Letters of credit outstanding
Letters of Credit Outstanding, Amount
Credit facilities unused
Line of Credit Facility, Remaining Borrowing Capacity
Short-term debt weighted average interest rate (percent)
Short-term Debt, Weighted Average Interest Rate
Current installments of long-term debt
Long-term debt weighted average interest rate (percent)
Long-term Debt, Weighted Average Interest Rate
Segmented Information
Segment Reporting Disclosure [Text Block]
Schedule of Stock by Class [Table]
Schedule of Stock by Class [Table]
Common Shares
Sale of Stock [Axis]
Sale of Stock [Axis]
Sale of Stock [Domain]
Sale of Stock [Domain]
Private Offering
Private Placement [Member]
Class of Stock [Line Items]
Class of Stock [Line Items]
Private Offering (shares)
Stock Issued During Period, Shares, New Issues
Private Offering
Private placement share consideration price (CAD per share)
Fair Value Hierarchy
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]
Schedule of Volume of Derivative Activity
Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]
Schedule of Financial Instruments Not Carried At Fair Value
Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block]
Derivative instruments
Deferred Derivative Gain (Loss) [Member]
Hedging Relationship [Axis]
Hedging Relationship [Axis]
Hedging Relationship [Domain]
Hedging Relationship [Domain]
Cash flow hedges
Cash Flow Hedging [Member]
Long-term debt due January 2018
Long-term Debt Due January Twenty Eighteen [Member]
Long-term Debt Due January Twenty Eighteen [Member]
Unrealized losses recognized in regulatory assets
Unrealized gains recognized in regulatory liabilities
Realized gains on contracts shared with customers (percent)
Realized Gains Shared With Customers, Percent
Realized Gains Shared With Customers, Percent
Notional amount
Derivative, Notional Amount
Original term
Derivative, Term of Contract
Loss expected to be reclassified to earnings
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months
Estimated effect of 5 cent change in exchange rate on EPS (percent)
Earnings Per Share, Effect Of Five-Cent Change On Exchange Rate
Earnings Per Share, Effect Of Five-Cent Change On Exchange Rate
Measurement Basis [Axis]
Measurement Basis [Axis]
Fair Value Measurement [Domain]
Fair Value Measurement [Domain]
Portion at Fair Value Measurement
Portion at Fair Value Measurement [Member]
Carrying Value
Reported Value Measurement [Member]
Estimated Fair Value
Estimate of Fair Value Measurement [Member]
Waneta Partnership
Long-term debt, including current portion (Note 6)
Long-term Debt, Fair Value
Waneta Partnership promissory note
Notes Payable, Fair Value Disclosure
Description of Business
Business Description and Basis of Presentation [Text Block]
Derivative Instruments and Hedging Activities Disclosures [Table]
Derivative Instruments and Hedging Activities Disclosures [Table]
Foreign net investments
Net Investment Hedging [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of hedged
Derivative, Amount of Hedged Item
Amount remaining to be hedged
Net Investment In Foreign Operation, Amount Not Hedged
Net Investment In Foreign Operation, Amount Not Hedged
Statement of Financial Position [Abstract]
Issued (shares)
Common Stock, Shares, Issued
Outstanding (shares)
Common Stock, Shares, Outstanding
Fixed-term debt
Fixed-Term Debt [Member]
Fixed-Term Debt [Member]
Revolving corporate credit facility
Revolving Credit Facility [Member]
Corporate
Fortis Inc. [Member]
Fortis Inc. [Member]
Bank concentration risk
Lender Concentration Risk [Member]
Committed facilities with maturities ranging from 2017 through 2022
Committed Credit Facilities Maturing 2017 through 2022 [Member]
Committed Credit Facilities Maturing 2017 through 2022 [Member]
Average annual fixed-term debt maturities and repayments over the next five years
Long-term Debt, Maturities, Average Repayments of Principal in Each of the Next Five Years
Long-term Debt, Maturities, Average Repayments of Principal in Each of the Next Five Years
Maximum borrowing capacity
Schedule of Preliminary Allocation of Purchase Consideration
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]
Supplemental Pro Forma Data
Business Acquisition, Pro Forma Information [Table Text Block]
Schedule of Error Corrections and Prior Period Adjustment Restatement [Table]
Schedule of Error Corrections and Prior Period Adjustment Restatement [Table]
Scenario [Axis]
Scenario [Axis]
Scenario, Unspecified [Domain]
Scenario, Unspecified [Domain]
Restatement adjustment
Restatement Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Electricity swap contracts
Electricity Swap Contracts, Subject to Regulatory Deferral [Member]
Electricity Swap Contracts, Subject to Regulatory Deferral [Member]
Electricity swap contracts, 2017
Electricity Swap Contracts, Subject to Regulatory Deferral, Remainder of Fiscal Year [Member]
Electricity Swap Contracts, Subject to Regulatory Deferral, Remainder of Fiscal Year [Member]
Electricity swap contracts, 2018
Electricity Swap Contracts, Subject to Regulatory Deferral, Year Two [Member]
Electricity Swap Contracts, Subject to Regulatory Deferral, Year Two [Member]
Electricity swap contracts, 2019
Electricity Swap Contracts, Subject to Regulatory Deferral, Year Three [Member]
Electricity Swap Contracts, Subject to Regulatory Deferral, Year Three [Member]
Electricity swap contracts, 2020
Electricity Swap Contracts, Subject to Regulatory Deferral, Year Four [Member]
Electricity Swap Contracts, Subject to Regulatory Deferral, Year Four [Member]
Electricity swap contracts, 2021
Electricity Swap Contracts, Subject to Regulatory Deferral, Year Five [Member]
Electricity Swap Contracts, Subject to Regulatory Deferral, Year Five [Member]
Electricity swap contracts thereafter
Electricity Swap Contracts, Subject to Regulatory Deferral, Thereafter [Member]
Electricity Swap Contracts, Subject to Regulatory Deferral, Thereafter [Member]
Electricity power purchase contracts
Electricity Power Purchase Contracts, Subject to Regulatory Deferral [Member]
Electricity Power Purchase Contracts, Subject to Regulatory Deferral [Member]
Electricity power purchase contracts, 2017
Electricity Power Purchase Contracts, Subject to Regulatory Deferral, Remainder of Fiscal Year [Member]
Electricity Power Purchase Contracts, Subject to Regulatory Deferral, Remainder of Fiscal Year [Member]
Electricity power purchase contracts, 2018
Electricity Power Purchase Contracts, Subject to Regulatory Deferral, Year Two [Member]
Electricity Power Purchase Contracts, Subject to Regulatory Deferral, Year Two
Electricity power purchase contracts, 2019
Electricity Power Purchase Contracts, Subject to Regulatory Deferral, Year Three [Member]
Electricity Power Purchase Contracts, Subject to Regulatory Deferral, Year Three [Member]
Electricity power purchase contracts, 2020
Electricity Power Purchase Contracts, Subject to Regulatory Deferral, Year Four [Member]
Electricity Power Purchase Contracts, Subject to Regulatory Deferral, Year Four [Member]
Electricity power purchase contracts, 2021
Electricity Power Purchase Contracts, Subject to Regulatory Deferral, Year Five [Member]
Electricity Power Purchase Contracts, Subject to Regulatory Deferral, Year Five [Member]
Electricity power purchase contracts, thereafter
Electricity Power Purchase Contracts, Subject to Regulatory Deferral, Thereafter [Member]
Electricity Power Purchase Contracts, Subject to Regulatory Deferral, Thereafter [Member]
Gas swap contracts
Gas Swap Contracts, Subject to Regulatory Deferral [Member]
Gas Swap Contracts, Subject to Regulatory Deferral [Member]
Gas swap contracts, 2017
Gas Swap Contracts, Subject to Regulatory Deferral, Remainder of Fiscal Year [Member]
Gas Swap Contracts, Subject to Regulatory Deferral, Remainder of Fiscal Year [Member]
Gas swap contracts, 2018
Gas Swap Contracts, Subject to Regulatory Deferral, Next Two [Member]
Gas Swap Contracts, Subject to Regulatory Deferral, Next Two [Member]
Gas swap contracts, 2019
Gas Swap Contracts, Subject to Regulatory Deferral, Next Three [Member]
Gas Swap Contracts, Subject to Regulatory Deferral, Next Three [Member]
Gas swap contracts, 2020
Gas Swap Contracts, Subject to Regulatory Deferral, Next Four [Member]
Gas Swap Contracts, Subject to Regulatory Deferral, Next Four [Member]
Gas swap contracts, 2021
Gas Swap Contracts, Subject to Regulatory Deferral, Next Five [Member]
Gas Swap Contracts, Subject to Regulatory Deferral, Next Five [Member]
Gas swap contracts, thereafter
Gas Swap Contracts, Subject to Regulatory Deferral, Thereafter [Member]
Gas Swap Contracts, Subject to Regulatory Deferral, Thereafter [Member]
Gas supply contract premiums, subject to regulatory deferral
Gas Supply Contract Premiums, Subject to Regulatory Deferral [Member]
Gas Supply Contract Premiums, Subject to Regulatory Deferral Member]
Gas supply contract premiums, subject to regulatory deferral, 2017
Gas Supply Contract Premiums, Subject to Regulatory Deferral, Remainder of Fiscal Year [Member]
Gas Supply Contract Premiums, Subject to Regulatory Deferral, Remainder of Fiscal Year [Member]
Gas supply contract premiums, subject to regulatory deferral, 2018
Gas Supply Contract Premiums, Subject to Regulatory Deferral, Year Two [Member]
Gas Supply Contract Premiums, Subject to Regulatory Deferral, Year Two
Gas supply contract premiums, subject to regulatory deferral, 2019
Gas Supply Contract Premiums, Subject to Regulatory Deferral, Year Three [Member]
Gas Supply Contract Premiums, Subject to Regulatory Deferral, Year Three
Gas supply contract premiums, subject to regulatory deferral, 2020
Gas Supply Contract Premiums, Subject to Regulatory Deferral, Year Four [Member]
Gas Supply Contract Premiums, Subject to Regulatory Deferral, Year Four
Gas supply contract premiums, subject to regulatory deferral, 2021
Gas Supply Contract Premiums, Subject to Regulatory Deferral, Year Five [Member]
Gas Supply Contract Premiums, Subject to Regulatory Deferral, Year Five
Gas supply contract premiums, subject to regulatory deferral, thereafter
Gas Supply Contract Premiums, Subject to Regulatory Deferral, Thereafter [Member]
Gas Supply Contract Premiums, Subject to Regulatory Deferral, Thereafter [Member]
Wholesale trading contracts
Wholesale Trading Contracts, Not Subject to Regulatory Deferral [Member]
Wholesale Trading Contracts, Not Subject to Regulatory Deferral [Member]
Wholesale trading contracts, 2017
Wholesale Trading Contracts, Not Subject to Regulatory Deferral, Remainder of Fiscal Year [Member]
Wholesale Trading Contracts, Not Subject to Regulatory Deferral, Remainder of Fiscal Year [Member]
Wholesale trading contracts, 2018
Wholesale Trading Contracts, Not Subject to Regulatory Deferral, Year Two [Member]
Wholesale Trading Contracts, Not Subject to Regulatory Deferral, Year Two [Member]
Wholesale trading contracts, 2019
Wholesale Trading Contracts, Not Subject to Regulatory Deferral, Year Three [Member]
Wholesale Trading Contracts, Not Subject to Regulatory Deferral, Year Three [Member]
Wholesale trading contracts, 2020
Wholesale Trading Contracts, Not Subject to Regulatory Deferral, Year Four [Member]
Wholesale Trading Contracts, Not Subject to Regulatory Deferral, Year Four [Member]
Wholesale trading contracts, 2021
Wholesale Trading Contracts, Not Subject to Regulatory Deferral, Year Five [Member]
Wholesale Trading Contracts, Not Subject to Regulatory Deferral, Year Five [Member]
Wholesale trading contracts, thereafter
Wholesale Trading Contracts, Not Subject to Regulatory Deferral, Thereafter [Member]
Wholesale Trading Contracts, Not Subject to Regulatory Deferral, Thereafter [Member]
Gas swap contracts
Gas Swap Contracts, Not Subject to Regulatory Deferral [Member]
Gas Swap Contracts, Not Subject to Regulatory Deferral [Member]
Gas swap contracts, not subject to regulatory deferral, 2017
Gas Swap Contracts, Not Subject to Regulatory Deferral, Remainder of Fiscal Year [Member]
Gas Swap Contracts, Not Subject to Regulatory Deferral, Remainder of Fiscal Year [Member]
Gas swap contracts, not subject to regulatory deferral, 2018
Gas Swap Contracts, Not Subject to Regulatory Deferral, Year Two [Member]
Gas Swap Contracts, Not Subject to Regulatory Deferral, Year Two [Member]
Gas swap contracts, not subject to regulatory deferral, 2019
Gas Swap Contracts, Not Subject to Regulatory Deferral, Year Three [Member]
Gas Swap Contracts, Not Subject to Regulatory Deferral, Year Three [Member]
Gas swap contracts, not subject to regulatory deferral, 2020
Gas Swap Contracts, Not Subject to Regulatory Deferral, Year Four [Member]
Gas Swap Contracts, Not Subject to Regulatory Deferral, Year Four [Member]
Gas swap contracts, not subject to regulatory deferral, 2021
Gas Swap Contracts, Not Subject to Regulatory Deferral, Year Five [Member]
Gas Swap Contracts, Not Subject to Regulatory Deferral, Year Five [Member]
Gas swap contracts, not subject to regulatory deferral, thereafter
Gas Swap Contracts, Not Subject to Regulatory Deferral, Thereafter [Member]
Gas Swap Contracts, Not Subject to Regulatory Deferral, Thereafter [Member]
Number of contracts
Derivative, Number of Instruments Held
Volume (gwh / kj)
Derivative, Nonmonetary Notional Amount, Energy Measure
Business Combination, Consideration Transferred [Abstract]
Business Combination, Consideration Transferred [Abstract]
Cash consideration
Total consideration
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest [Abstract]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest [Abstract]
Purchase consideration for 80.1% of ITC common shares
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest
19.9% minority shareholder investment and shareholder note
Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value
Total consideration
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net
Fair value assigned to net assets:
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Current assets
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets
Long-term regulatory assets
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Regulatory Assets, Noncurrent
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Regulatory Assets, Noncurrent
Capital assets, net
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Public Utilities, Property, Plant, and Equipment
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Public Utilities, Property, Plant, and Equipment
Intangible assets, net
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill
Other long-term assets
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets
Current liabilities
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities
Assumed short-term borrowings
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Short-term Debt
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Short-term Debt
Assumed long-term debt (including current portion)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt
Long-term regulatory liabilities
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Regulatory Liabilities, Noncurrent
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Regulatory Liabilities, Noncurrent
Deferred income taxes
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities
Other long-term liabilities
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other
Fair value of net assets acquired, excluding cash and cash equivalents
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net, Excluding Cash and Cash Equivalents
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net, Excluding Cash and Cash Equivalents
Cash and cash equivalents
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents
Fair value of net assets acquired
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net
Regulatory Assets and Liabilities
Schedule of Regulatory Assets and Liabilities [Text Block]
Dividends declared (CAD per share)
Common Stock, Dividends, Per Share, Declared
Schedule of Defined Benefit Plans Disclosures [Table]
Schedule of Defined Benefit Plans Disclosures [Table]
Defined Benefit Plans and Other Postretirement Benefit Plans [Axis]
Defined Benefit Plans and Other Postretirement Benefit Plans [Axis]
Defined Benefit Plan and Other Postretirement Benefit Plan [Domain]
Defined Benefit Plan and Other Postretirement Benefit Plan [Domain]
Defined Benefit Pension Plans
Pension Plan [Member]
OPEB Plans
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service costs
Defined Benefit Plan, Service Cost
Interest costs
Defined Benefit Plan, Interest Cost
Expected return on plan assets
Defined Benefit Plan, Expected Return on Plan Assets
Amortization of actuarial losses
Defined Benefit Plan, Amortization of Gains (Losses)
Amortization of past service credits/plan amendments
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)
Regulatory adjustments
Defined Benefit Plan, Regulatory Adjustments
Defined Benefit Plan, Regulatory Adjustments
Net benefit cost
Defined Benefit Plan, Net Periodic Benefit Cost
PSUs
Performance Shares [Member]
PSU 2015 Plan
PSU 2015 Plan [Member]
PSU 2015 Plan [Member]
Range [Axis]
Range [Axis]
Range [Domain]
Range [Domain]
Minimum
Minimum [Member]
Maximum
Maximum [Member]
Senior management
Management [Member]
Award Date [Axis]
Award Date [Axis]
Award Date [Domain]
Award Date [Domain]
Granted in 2014
Granted In 2014 [Member]
Granted In 2014 [Member]
Estimated payout (percent)
Share-based Compensation Arrangement by Share-based Payment Award, Maturity Payout, Estimated, Percent
Share-based Compensation Arrangement by Share-based Payment Award, Maturity Payout, Estimated, Percent
Awards paid out (shares)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period
Awards paid out, weighted average exercise price (cad per share)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Paid Out, Weighted Average Payout Price
Share-based Compensation Arrangement by Share-based Payment Award, Options, Paid Out, Weighted Average Payout Price
Total paid out to senior management
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value
Payout (percent)
Share-based Compensation Arrangement by Share-based Payment Award, Maturity Payout, Percent
Share-based Compensation Arrangement by Share-based Payment Award, Maturity Payout, Percent
Schedule of Information by Reportable Segment
Schedule of Segment Reporting Information, by Segment [Table Text Block]
Schedule of Significant Inter-company Transactions
Schedule of Intercompany Profit to Regulated Affiliates [Table Text Block]
Schedule of Intercompany Profit to Regulated Affiliates [Table Text Block]
Schedule of Long-Term Debt
Schedule of Long-term Debt Instruments [Table Text Block]
Change in working capital:
Additional Cash Flow Elements, Operating Activities [Abstract]
Accounts receivable and other current assets
Increase (Decrease) in Accounts Receivable and Other Operating Assets
Prepaid expenses
Increase (Decrease) in Prepaid Expense
Inventories
Increase (Decrease) in Inventories
Regulatory assets - current portion
Increase (Decrease) in Other Regulatory Assets
Accounts payable and other current liabilities
Increase (Decrease) in Accounts Payable and Other Operating Liabilities
Regulatory liabilities - current portion
Increase (Decrease) in Regulatory Liabilities
Changes in working capital
Increase (Decrease) in Operating Capital
Non-cash investing and financing activities:
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Accrued capital expenditures
Capital Expenditures Incurred but Not yet Paid
Common share dividends reinvested
Stock Issued
Transfer of deposit on business acquisition (Note 16)
Transfer of Deposit Related to Business Acquisition
Transfer of Deposit Related to Business Acquisition
Contributions in aid of construction
Contributions in Aid of Construction Included in Current Assets
Contributions in Aid of Construction Included in Current Assets
Exercise of stock options into common shares
Conversion of Stock, Amount Issued
Number of Shares
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Balance, beginning of period (shares)
Shares, Issued
Dividend Reinvestment Plan (shares)
Stock Issued During Period, Shares, Dividend Reinvestment Plan
Stock Option Plans (shares)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period
Employee Share Purchase Plan (shares)
Stock Issued During Period, Shares, Employee Stock Purchase Plans
Consumer Share Purchase Plan (shares)
Stock Issued During Period, Shares, Consumer Stock Purchase Plans
Stock Issued During Period, Shares, Consumer Stock Purchase Plans
Conversion of Convertible Debentures (shares)
Stock Issued During Period, Shares, Conversion of Convertible Securities
Balance, end of period (shares)
Common Shares, Amount [Abstract]
Common Shares, Amount [Abstract]
Common Shares, Amount [Abstract]
Dividend Reinvestment Plan
Stock Issued During Period, Value, Dividend Reinvestment Plan
Stock Option Plans
Stock Issued During Period, Value, Stock Options Exercised
Employee Share Purchase Plan
Stock Issued During Period, Value, Employee Stock Purchase Plan
Consumer Share Purchase Plan
Stock Issued During Period, Value, Consumer Stock Purchase Plans
Stock Issued During Period, Value, Consumer Stock Purchase Plans
Conversion of Convertible Debentures
Stock Issued During Period, Value, Conversion of Convertible Securities, Net of Adjustments
Statement of Comprehensive Income [Abstract]
Other comprehensive (loss) income
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Unrealized foreign currency translation losses, net of hedging activities and tax
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax
Net change in available-for-sale investment, net of tax
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax
Net change in fair value of cash flow hedges, net of tax
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax
Other comprehensive (loss) income
Comprehensive income
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest
Comprehensive income attributable to:
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Non-controlling interests
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest
Preference equity shareholders
Common equity shareholders
Comprehensive Income (Loss) Available To Common Stockholders, Basic
Comprehensive Income (Loss) Available To Common Stockholders, Basic
Pro forma revenue
Business Acquisition, Pro Forma Revenue
Pro forma net earnings attributable to common equity shareholders
Business Acquisition, Pro Forma Net Income (Loss)
Statement of Cash Flows [Abstract]
Operating activities
Net Cash Provided by (Used in) Operating Activities [Abstract]
Adjustments to reconcile net earnings to net cash provided by operating activities:
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Depreciation - capital assets
Depreciation
Amortization - intangible assets
Amortization of Intangible Assets
Amortization - other
Amortization of Other Deferred Charges
Deferred income tax expense
Deferred Income Tax Expense (Benefit)
Accrued employee future benefits
Employee Benefits and Share-based Compensation
Equity component of allowance for funds used during construction (Note 10)
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity
Other
Other Operating Activities, Cash Flow Statement
Change in long-term regulatory assets and liabilities
Increase (Decrease) In Regulatory Assets And Liabilities, Noncurrent
Increase (Decrease) In Regulatory Assets And Liabilities, Noncurrent
Change in working capital (Note 13)
Cash from operating activities
Net Cash Provided by (Used in) Operating Activities
Investing activities
Net Cash Provided by (Used in) Investing Activities [Abstract]
Capital expenditures - capital assets
Payments to Acquire Property, Plant, and Equipment
Capital expenditures - intangible assets
Payments to Acquire Intangible Assets
Contributions in aid of construction
Proceeds from Contribution in Aid of Construction
Proceeds on sale of assets
Proceeds from Sale of Productive Assets
Business acquisitions, net of cash acquired (Note 16)
Other
Increase (Decrease) In Other Assets And Other Liabilities, Net, Investing Activities
Increase (Decrease) In Other Assets And Other Liabilities, Net, Investing Activities
Cash used in investing activities
Net Cash Provided by (Used in) Investing Activities
Financing activities
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from long-term debt, net of issue costs
Proceeds from Issuance of Long-term Debt
Repayments of long-term debt and capital lease and finance obligations
Repayments of Long-term Debt, Long-term Capital Lease Obligations, and Capital Securities
Net (repayments) borrowings under committed credit facilities
Proceeds from (Repayments of) Other Debt
Change in short-term borrowings, net
Proceeds from (Repayments of) Short-term Debt
Advances from non-controlling interests
Issue of common shares to an institutional investor (Note 7)
Proceeds from Issuance of Private Placement
Issue of common shares, net of costs and dividends reinvested
Proceeds from Issuance of Common Stock
Dividends
Payments of Ordinary Dividends [Abstract]
Common shares, net of dividends reinvested
Payments of Ordinary Dividends, Common Stock
Preference shares
Payments of Ordinary Dividends, Preferred Stock and Preference Stock
Subsidiary dividends paid to non-controlling interests
Payments of Ordinary Dividends, Noncontrolling Interest
Other
Proceeds from (Payments for) Other Financing Activities
Cash from financing activities
Net Cash Provided by (Used in) Financing Activities
Effect of exchange rate changes on cash and cash equivalents
Effect of Exchange Rate on Cash and Cash Equivalents
Change in cash and cash equivalents
Cash and Cash Equivalents, Period Increase (Decrease)
Cash and cash equivalents, beginning of period
Cash and Cash Equivalents, at Carrying Value
Cash and cash equivalents, end of period
Other Income and Expenses [Abstract]
Other Income, Net
Other Income and Other Expense Disclosure [Text Block]
Schedule of Other Income, Net
Schedule of Other Nonoperating Income (Expense) [Table Text Block]
Finance Charges
Interest Income and Interest Expense Disclosure [Table Text Block]
Forecast
Scenario, Forecast [Member]
BC Hydro
BC Hydro [Member]
BC Hydro [Member]
Teck
Teck Metals Ltd. [Member]
Teck Metals Ltd. [Member]
Pending Acquisition of an Interest in Waneta Dam
Teck Resources Limited, Waneta Dam And Related Transmission Assets [Member]
Teck Resources Limited, Waneta Dam And Related Transmission Assets [Member]
Long-term contract for electric power, term
Long-Term Contract For Electric Power, Contract Term
Long-Term Contract For Electric Power, Contract Term
Long-term contract for electric power extension, term
Long-Term Contract For Electric Power, Contract Term Extension
Long-Term Contract For Electric Power, Contract Term Extension
Percentage of ownership interest
Business Acquisition, Percentage of Voting Interests Acquired
Percentage of ownership interest not acquired
Business Acquisition, Percentage of Voting Interests Not Acquired
Business Acquisition, Percentage of Voting Interests Not Acquired
Interest:
Interest Expense [Abstract]
Long-term debt and capital lease and finance obligations
Interest Expense, Long-term Debt
Short-term borrowings
Interest Expense, Short-term Borrowings
Acquisition credit facilities
Business Combination, Acquisition Related Costs, Nonoperating
Business Combination, Acquisition Related Costs, Nonoperating
Debt component of AFUDC
Public Utilities, Allowance for Funds Used During Construction, Debt Component
Public Utilities, Allowance for Funds Used During Construction, Debt Component
Finance charges
Entities [Table]
Entities [Table]
Entity Information [Line Items]
Entity Information [Line Items]
Equity component of allowance for funds used during construction (“AFUDC”)
Interest income
Investment Income, Interest
Equity income - Belize Electricity
Income (Loss) from Equity Method Investments
Other
Other Nonoperating Income (Expense)
Other income, net
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table]
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table]
Antidilutive Securities [Axis]
Antidilutive Securities [Axis]
Antidilutive Securities, Name [Domain]
Antidilutive Securities, Name [Domain]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net Earnings to Common Shareholders
Net Income (Loss) Available to Common Stockholders, Diluted [Abstract]
Basic EPS
Effect of potential dilutive securities:
Dilutive Securities, Effect on Basic Earnings Per Share [Abstract]
Stock Options
Dilutive Securities, Effect on Basic Earnings Per Share, Options and Restrictive Stock Units
Preference Shares
Dilutive Securities, Effect on Basic Earnings Per Share, Dilutive Convertible Securities
Potentially Dilutive Securities
Net Income (Loss) Attributable to Parent, Potentially Diluted
Net Income (Loss) Attributable to Parent, Potentially Diluted
Deduct anti-dilutive impacts:
Anti-Dilutive Securities, Deducted, Amount [Abstract]
Anti-Dilutive Securities, Deducted, Amount [Abstract]
Preference Shares
Antidilutive Securities Excluded from Computation of EPS
Antidilutive Securities Excluded from Computation of EPS
Diluted EPS
Net Income (Loss) Attributable to Parent, Diluted
Weighted Average Shares
Weighted Average Number of Shares Outstanding, Diluted [Abstract]
Basic EPS (shares)
Weighted Average Number of Shares Outstanding, Basic
Effect of potential dilutive securities:
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Stock Options (shares)
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements
Preference Shares (shares)
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock
Potentially Dilutive Securities (shares)
Weighted Average Number of Shares Outstanding, Potentially Diluted
Weighted Average Number of Shares Outstanding, Potentially Diluted
Deduct anti-dilutive impacts:
Weighted Average Shares Attributable to Anti-Dilutive Effect [Abstract]
Weighted Average Shares Attributable to Anti-Dilutive Effect [Abstract]
Preference Shares (shares)
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount
Diluted EPS (shares)
Weighted Average Number of Shares Outstanding, Diluted
EPS
Earnings Per Share, Diluted [Abstract]
Schedule of Net Benefit Costs
Schedule of Net Benefit Costs [Table Text Block]
ASSETS
Assets [Abstract]
Current assets
Assets, Current [Abstract]
Cash and cash equivalents
Accounts receivable and other current assets
Accounts and Other Receivables, Net, Current
Prepaid expenses
Prepaid Expense, Current
Inventories
Public Utilities, Inventory
Regulatory assets (Note 5)
Total current assets
Assets, Current
Other assets
Other Assets, Noncurrent
Regulatory assets (Note 5)
Capital assets, net
Public Utilities, Property, Plant and Equipment, Net
Intangible assets, net
Intangible Assets, Net (Excluding Goodwill)
LIABILITIES AND EQUITY
Liabilities and Equity [Abstract]
Current liabilities
Liabilities, Current [Abstract]
Short-term borrowings (Note 15)
Accounts payable and other current liabilities
Accounts Payable and Other Accrued Liabilities, Current
Regulatory liabilities (Note 5)
Current installments of long-term debt (Note 6)
Current installments of capital lease and finance obligations
Capital Lease Obligations, Current
Total current liabilities
Liabilities, Current
Other liabilities
Other Liabilities, Noncurrent
Regulatory liabilities (Note 5)
Deferred income taxes
Deferred Income Tax Liabilities, Net
Long-term debt (Note 6)
Capital lease and finance obligations
Capital Lease Obligations, Noncurrent
Total liabilities
Liabilities
Commitments and Contingencies (Note 17)
Commitments and Contingencies
Equity
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Common shares (Note 7)
Common Stock, Value, Issued
Preference shares
Preferred Stock, Value, Issued
Additional paid-in capital
Additional Paid in Capital, Common Stock
Accumulated other comprehensive income
Accumulated Other Comprehensive Income (Loss), Net of Tax
Retained earnings
Retained Earnings (Accumulated Deficit)
Shareholders’ equity
Stockholders' Equity Attributable to Parent
Non-controlling interests
Stockholders' Equity Attributable to Noncontrolling Interest
Total equity
Total liabilities and equity
Liabilities and Equity
Comparative Figures
Reclassifications [Text Block]
Stock‑based compensation expense
Allocated Share-based Compensation Expense
Options granted (shares)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross
Volume weighted average share price (period)
Share-Based Compensation Arrangement By Share-based Payment Award, Fair Value Assumptions, Volume Weighted Average Price, Period
Share-Based Compensation Arrangement By Share-based Payment Award, Fair Value Assumptions, Volume Weighted Average Price, Period
Exercise price (CAD per share)
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price
Exercisable period
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period
Expiration period after termination, death or retirement
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period After Termination, Death or Retirement
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period After Termination, Death or Retirement
Grant date fair value (CAD per share)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value