Supplementary Cash Flow Information (Details) - CAD ($) $ in Millions	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023
Cash paid (received) for
Interest	$ 1,361	$ 1,255
Income taxes	(17)	129
Change in working capital
Accounts receivable and other current assets	(2)	142
Prepaid expenses	(21)	(7)
Inventories	(73)	(1)
Regulatory assets - current portion	93	104
Accounts payable and other current liabilities	115	(390)
Regulatory liabilities - current portion	56	71
Change in working capital	168	(81)
Non-cash financing activity
Common share dividends reinvested	434	408
Non-cash investing and financing activities
Accrued capital expenditures	722	516
Contributions in aid of construction	$ 14	$ 15

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Contributions in Aid of Construction, Non-cash

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Future cash outflow to pay for purchases of fixed assets that have occurred.

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Amount, after refund, of cash paid to foreign, federal, state, and local jurisdictions as income tax.

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Amount of increase (decrease) in obligations incurred but not paid, and operating obligations classified as other.

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The increase (decrease) during the reporting period in the aggregate value of all inventory held by the reporting entity, associated with underlying transactions that are classified as operating activities.

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Amount of cash paid for interest, excluding capitalized interest, classified as operating activity. Includes, but is not limited to, payment to settle zero-coupon bond for accreted interest of debt discount and debt instrument with insignificant coupon interest rate in relation to effective interest rate of borrowing attributable to accreted interest of debt discount.

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The fair value of stock issued in noncash financing activities.

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