INCOME TAXES - DEFERRED INCOME TAXES (Details) - CAD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Deferred income tax liabilities
Property, plant and equipment	$ (7,290)	$ (7,018)
Investments	(4,620)	(4,441)
Regulatory assets	(1,052)	(756)
Other	(40)	(192)
Total deferred income tax liabilities	(13,002)	(12,407)
Deferred income tax assets
Financial instruments	679	1,103
Pension and OPEB plans	206	181
Loss carryforwards	1,693	1,820
Other	1,641	1,274
Total deferred income tax assets	4,219	4,378
Less valuation allowance	(84)	(51)
Total deferred income tax assets, net	4,135	4,327
Net deferred income tax liabilities	(8,867)	(8,080)
Total deferred income tax assets	1,000	1,374
Total deferred income tax liabilities	(9,867)	(9,454)
Foreign subsidiaries' undistributed earnings on which deferred income taxes has not been provided	5,300	5,800
Canada
Deferred income tax assets
Benefit of unused tax loss carryforwards recognized	3,200	3,400
United States
Deferred income tax assets
Benefit of unused tax loss carryforwards recognized	$ 3,600	$ 3,400