VARIABLE INTEREST ENTITIES - Schedule of Assets and Liabilities of Consolidated VIEs (Details) - CAD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Assets
Cash and cash equivalents	$ 286	$ 452
Restricted cash	34	38
Accounts receivable and other	6,862	5,258
Inventory	1,670	1,536
Current assets	8,959	7,350
Property, plant and equipment, net	100,067	94,571	$ 93,723
Long-term investments	13,324	13,818
Restricted long-term investments	630	553
Deferred amounts and other assets	8,613	8,446
Intangible assets, net	4,008	2,080
Total assets	168,864	160,276
Liabilities
Accounts payable and other	9,767	9,228
Other long-term liabilities	7,617	8,783
Deferred income taxes	11,689	10,332
Liabilities	105,496	95,913
Variable Interest Entity, Primary Beneficiary
Assets
Cash and cash equivalents	247	215
Restricted cash	4	1
Accounts receivable and other	99	65
Inventory	9	7
Current assets	359	288
Property, plant and equipment, net	3,052	3,201
Long-term investments	16	14
Restricted long-term investments	101	84
Deferred amounts and other assets	2	3
Intangible assets, net	108	115
Total assets	3,638	3,705
Liabilities
Accounts payable and other	84	52
Other long-term liabilities	182	175
Deferred income taxes	5	5
Liabilities	271	232
Net Assets	$ 3,367	$ 3,473