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Income Taxes (Deferred income tax assets and liabilities) (Details) - CAD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Deferred income tax assets: |  |
Tax loss carryforwards | $ 724 | $ 908
Tax credit carryforwards | 319 | 311
Regulatory liabilities - cost of removal | 184 | 195
Derivative instruments | 108 | 145
Other | 375 | 413
Total deferred income tax assets before valuation allowance | 1,710 | 1,972
Total deferred income tax assets after valuation allowance | 1,508 | 1,779
Deferred income tax (liabilities): |  |
Property, plant and equipment | (2,450) | (2,382)
Derivative instruments | (93) | (148)
Other | (385) | (348)
Total deferred income tax liabilities | (2,928) | (2,878)
Consolidated Balance Sheets presentation: |  |
Long-term deferred income tax assets | 209 | 186
Long-term deferred income tax liabilities | (1,629) | (1,285)
Net deferred income tax liabilities | $ (1,420) | $ (1,099)

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