COMPONENTS OF ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) (Details) - CAD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Changes in AOCI
Balance at the beginning of the period	$ 63,368
Other comprehensive income/(loss) retained in AOCI	5,010	$ (74)
Other	16
Total before tax impact	5,203	166
Income tax on amounts retained in AOCI	(243)	(69)
Income tax on amounts reclassified to earnings	(39)	(56)
Tax impact	(282)	(125)
Balance at the end of the period	67,430	64,662
Interest rate contracts
Changes in AOCI
Other comprehensive loss/(income) reclassified to earnings	187	218
Foreign exchange contracts
Changes in AOCI
Other comprehensive loss/(income) reclassified to earnings	(4)	4
Other contracts
Changes in AOCI
Other comprehensive loss/(income) reclassified to earnings	3	1
Commodity contracts
Changes in AOCI
Other comprehensive loss/(income) reclassified to earnings		(4)
Total
Changes in AOCI
Balance at the beginning of the period	(1,096)	(1,401)
Balance at the end of the period	3,825	(1,360)
Cash Flow Hedges
Changes in AOCI
Balance at the beginning of the period	(897)	(1,326)
Other comprehensive income/(loss) retained in AOCI	1,073	284
Other		17
Total before tax impact	1,259	520
Income tax on amounts retained in AOCI	(242)	(72)
Income tax on amounts reclassified to earnings	(41)	(51)
Tax impact	(283)	(123)
Balance at the end of the period	79	(929)
Cash Flow Hedges | Interest rate contracts
Changes in AOCI
Other comprehensive loss/(income) reclassified to earnings	187	218
Cash Flow Hedges | Foreign exchange contracts
Changes in AOCI
Other comprehensive loss/(income) reclassified to earnings	(4)	4
Cash Flow Hedges | Other contracts
Changes in AOCI
Other comprehensive loss/(income) reclassified to earnings	3	1
Cash Flow Hedges | Commodity contracts
Changes in AOCI
Other comprehensive loss/(income) reclassified to earnings		(4)
Excluded Components of Fair Value Hedges
Changes in AOCI
Balance at the beginning of the period	0	5
Other comprehensive income/(loss) retained in AOCI	(38)	(3)
Total before tax impact	(38)	(3)
Tax impact	0	0
Balance at the end of the period	(38)	2
Net Investment Hedges
Changes in AOCI
Balance at the beginning of the period	(166)	(215)
Other comprehensive income/(loss) retained in AOCI	(1,187)	18
Total before tax impact	(1,187)	18
Income tax on amounts retained in AOCI		(2)
Tax impact	0	(2)
Balance at the end of the period	(1,353)	(199)
Cumulative Translation Adjustment
Changes in AOCI
Balance at the beginning of the period	56	568
Other comprehensive income/(loss) retained in AOCI	5,168	(340)
Other		(20)
Total before tax impact	5,168	(360)
Tax impact	0	0
Balance at the end of the period	5,224	208
Equity Investees
Changes in AOCI
Balance at the beginning of the period	(5)	66
Other comprehensive income/(loss) retained in AOCI	(6)	(33)
Other	(16)	3
Total before tax impact	10	(30)
Income tax on amounts retained in AOCI	(1)	5
Tax impact	(1)	5
Balance at the end of the period	4	41
Pension and OPEB Adjustment
Changes in AOCI
Balance at the beginning of the period	(84)	(499)
Other comprehensive loss/(income) reclassified to earnings	(9)	21
Total before tax impact	(9)	21
Income tax on amounts reclassified to earnings	2	(5)
Tax impact	2	(5)
Balance at the end of the period	$ (91)	$ (483)