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Income Taxes (Deferred income tax assets and liabilities) (Details) - CAD ($) $ in Millions | Dec. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Deferred income tax assets: |  |
Tax loss carryforwards | $ 908 | $ 917
Tax credit carry forwards | 311 | 269
Regulatory liabilities - cost of removal | 195 | 206
Derivative instruments | 145 | 90
Pension and post-retirement liabilities | 84 | 126
Other | 329 | 441
Total deferred income tax assets before valuation allowance | 1,972 | 2,049
Valuation allowance | (193) | (163)
Total deferred income tax assets after valuation allowance | 1,779 | 1,886
Deferred income tax (liabilities): |  |
Property, plant and equipment | (2,382) | (2,591)
Derivative instruments | (148) | (124)
Other | (348) | (316)
Total deferred income tax liabilities | (2,878) | (3,031)
Consolidated Balance Sheets presentation: |  |
Long-term deferred income tax assets | 186 | 175
Long-term deferred income tax liabilities | (1,285) | (1,320)
Net deferred income tax liabilities | $ (1,099) | $ (1,145)

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