SHARE CAPITAL - Schedule of Preference Shares and Characteristics of Preference Shares (Details) $ / shares in Units, $ in Millions				3 Months Ended							12 Months Ended
	Sep. 01, 2024 shares	Sep. 01, 2023 shares	Jun. 01, 2023 shares	Dec. 31, 2024 CAD ($) $ / shares shares	Sep. 30, 2024 $ / shares	Jun. 30, 2024 $ / shares	Mar. 31, 2024 $ / shares	Mar. 31, 2024 $ / shares	Dec. 31, 2023 CAD ($) $ / shares shares	Dec. 31, 2023 CAD ($) $ / shares shares	Dec. 31, 2024 CAD ($) $ / shares shares	Dec. 31, 2024 CAD ($) $ / shares $ / shares shares	Dec. 31, 2023 CAD ($) shares	Dec. 31, 2022 CAD ($) shares	Dec. 31, 2024 $ / shares
Preferred Shares
Share Capital
Preferred stock, value, outstanding | $				$ 6,818					$ 6,818	$ 6,818	$ 6,818	$ 6,818	$ 6,818	$ 6,818
Issuance costs | $											$ (135)		$ (135)	$ (135)
Per share base redemption value (in Canadian dollars per shares)				$ 25							$ 25	$ 25
Preference shares conversion ratio				1							1	1
Preference Shares, Series A
Share Capital
Dividend (in Canadian dollars per share)											$ 1.37500
Preference Shares, Series A | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares				5,000,000					5,000,000	5,000,000	5,000,000	5,000,000	5,000,000	5,000,000
Preferred stock, value, outstanding | $				$ 125					$ 125	$ 125	$ 125	$ 125	$ 125	$ 125
Dividend rate (percent)											5.50%
Per share base redemption value (in Canadian dollars per shares)				$ 25							$ 25	$ 25
Dividend rate reset period (in years)											5 years
Preference Shares, Series B
Share Capital
Dividend (in Canadian dollars per share)											$ 1.30052
Preference Shares, Series B | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares				20,000,000					20,000,000	20,000,000	20,000,000	20,000,000	20,000,000	20,000,000
Preferred stock, value, outstanding | $				$ 500					$ 500	$ 500	$ 500	$ 500	$ 500	$ 500
Dividend rate (percent)											5.20%
Per share base redemption value (in Canadian dollars per shares)				$ 25							$ 25	$ 25
Preference Shares, Series C | Preferred Shares | 3-Month Government Of Canada Treasury Bill
Share Capital
Dividend rate -spread on variable rate (percent)				2.40%							2.40%	2.40%
Preference Shares, Series D
Share Capital
Dividend (in Canadian dollars per share)											$ 1.35300
Preference Shares, Series D | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares				18,000,000					18,000,000	18,000,000	18,000,000	18,000,000	18,000,000	18,000,000
Preferred stock, value, outstanding | $				$ 450					$ 450	$ 450	$ 450	$ 450	$ 450	$ 450
Dividend rate (percent)											5.41%
Per share base redemption value (in Canadian dollars per shares)				$ 25							$ 25	$ 25
Preference Shares, Series F
Share Capital
Dividend (in Canadian dollars per share)											$ 1.38452
Preference Shares, Series F | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares				18,000,000					18,000,000	18,000,000	18,000,000	18,000,000	18,000,000	20,000,000
Preferred stock, value, outstanding | $				$ 454					$ 454	$ 454	$ 454	$ 454	$ 454	$ 500
Dividend rate (percent)											5.54%
Per share base redemption value (in Canadian dollars per shares)				$ 25							$ 25	$ 25
Conversion of stock, shares converted (shares) | shares			1,827,695
Preference Shares, Series G
Share Capital
Dividend (in Canadian dollars per share)				$ 0.37911	$ 0.43014						$ 1.51644
Preference Shares, Series G | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares				2,000,000					2,000,000	2,000,000	2,000,000	2,000,000	2,000,000	0
Preferred stock, value, outstanding | $				$ 46					$ 46	$ 46	$ 46	$ 46	$ 46	$ 0
Dividend rate (percent)											6.15%
Per share base redemption value (in Canadian dollars per shares)				$ 25							$ 25	$ 25
Conversion of stock, shares issued (shares) | shares			1,827,695
Preference Shares, Series G | Preferred Shares | 3-Month Government Of Canada Treasury Bill
Share Capital
Dividend rate -spread on variable rate (percent)				2.50%							2.50%	2.50%
Preference Shares, Series H
Share Capital
Dividend (in Canadian dollars per share)											$ 1.52800
Preference Shares, Series H | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares				12,000,000					12,000,000	12,000,000	12,000,000	12,000,000	12,000,000	14,000,000
Preferred stock, value, outstanding | $				$ 291					$ 291	$ 291	$ 291	$ 291	$ 291	$ 350
Dividend rate (percent)											6.11%
Per share base redemption value (in Canadian dollars per shares)				$ 25							$ 25	$ 25
Conversion of stock, shares converted (shares) | shares		2,350,602
Preference Shares, Series I
Share Capital
Dividend (in Canadian dollars per share)				$ 0.35507	0.40589						$ 1.42028
Preference Shares, Series I | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares				2,000,000					2,000,000	2,000,000	2,000,000	2,000,000	2,000,000	0
Preferred stock, value, outstanding | $				$ 59					$ 59	$ 59	$ 59	$ 59	$ 59	$ 0
Dividend rate (percent)											5.76%
Per share base redemption value (in Canadian dollars per shares)				$ 25							$ 25	$ 25
Conversion of stock, shares issued (shares) | shares		2,350,602
Preference Shares, Series I | Preferred Shares | 3-Month Government Of Canada Treasury Bill
Share Capital
Dividend rate -spread on variable rate (percent)				2.10%							2.10%	2.10%
Preference Shares, Series L
Share Capital
Dividend (in Canadian dollars per share)												$ 1.46448
Preference Shares, Series L | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares				16,000,000					16,000,000	16,000,000	16,000,000	16,000,000	16,000,000	16,000,000
Preferred stock, value, outstanding | $				$ 411					$ 411	$ 411	$ 411	$ 411	$ 411	$ 411
Dividend rate (percent)											5.86%
Per share base redemption value (in Canadian dollars per shares)															$ 25
Preference Shares, Series N
Share Capital
Dividend (in Canadian dollars per share)											$ 1.67400
Preference Shares, Series N | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares				18,000,000					18,000,000	18,000,000	18,000,000	18,000,000	18,000,000	18,000,000
Preferred stock, value, outstanding | $				$ 450					$ 450	$ 450	$ 450	$ 450	$ 450	$ 450
Dividend rate (percent)											6.70%
Per share base redemption value (in Canadian dollars per shares)				$ 25							$ 25	$ 25
Preference Shares, Series P
Share Capital
Dividend (in Canadian dollars per share)							$ 0.36988		$ 0.27369		$ 1.47952
Preference Shares, Series P | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares				16,000,000					16,000,000	16,000,000	16,000,000	16,000,000	16,000,000	16,000,000
Preferred stock, value, outstanding | $				$ 400					$ 400	$ 400	$ 400	$ 400	$ 400	$ 400
Dividend rate (percent)											5.92%
Per share base redemption value (in Canadian dollars per shares)				$ 25							$ 25	$ 25
Preference Shares, Series R
Share Capital
Dividend (in Canadian dollars per share)						$ 0.39463	0.25456				$ 1.57852
Preference Shares, Series R | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares				16,000,000					16,000,000	16,000,000	16,000,000	16,000,000	16,000,000	16,000,000
Preferred stock, value, outstanding | $				$ 400					$ 400	$ 400	$ 400	$ 400	$ 400	$ 400
Dividend rate (percent)											6.31%
Per share base redemption value (in Canadian dollars per shares)				$ 25							$ 25	$ 25
Preference Shares, Series 1
Share Capital
Dividend (in Canadian dollars per share)												$ 1.67592
Preference Shares, Series 1 | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares				16,000,000					16,000,000	16,000,000	16,000,000	16,000,000	16,000,000	16,000,000
Preferred stock, value, outstanding | $				$ 411					$ 411	$ 411	$ 411	$ 411	$ 411	$ 411
Dividend rate (percent)											6.70%
Per share base redemption value (in Canadian dollars per shares)															25
Preference Shares, Series 3
Share Capital
Dividend (in Canadian dollars per share)					0.33050	$ 0.23356					$ 1.32200
Conversion of stock, shares converted (shares) | shares	1,502,775
Preference Shares, Series 3 | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares				22,000,000					24,000,000	24,000,000	22,000,000	22,000,000	24,000,000	24,000,000
Preferred stock, value, outstanding | $				$ 562					$ 600	$ 600	$ 562	$ 562	$ 600	$ 600
Dividend rate (percent)											5.29%
Per share base redemption value (in Canadian dollars per shares)				$ 25							$ 25	$ 25
Preference Shares, Series 4
Share Capital
Dividend (in Canadian dollars per share)				$ 0.37110	0.42206						$ 1.48440
Conversion of stock, shares issued (shares) | shares	1,502,775
Preference Shares, Series 4 | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares				2,000,000					0	0	2,000,000	2,000,000	0	0
Preferred stock, value, outstanding | $				$ 38					$ 0	$ 0	$ 38	$ 38	$ 0	$ 0
Dividend rate (percent)											6.02%
Per share base redemption value (in Canadian dollars per shares)				$ 25							$ 25	$ 25
Preference Shares, Series 5
Share Capital
Dividend (in Canadian dollars per share)								$ 0.41769		$ 0.33596		$ 1.67076
Preference Shares, Series 5 | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares				8,000,000					8,000,000	8,000,000	8,000,000	8,000,000	8,000,000	8,000,000
Preferred stock, value, outstanding | $				$ 206					$ 206	$ 206	$ 206	$ 206	$ 206	$ 206
Dividend rate (percent)											6.68%
Per share base redemption value (in Canadian dollars per shares)															$ 25
Preference Shares, Series 7
Share Capital
Dividend (in Canadian dollars per share)							$ 0.37425		$ 0.27806		$ 1.49700
Preference Shares, Series 7 | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares				10,000,000					10,000,000	10,000,000	10,000,000	10,000,000	10,000,000	10,000,000
Preferred stock, value, outstanding | $				$ 250					$ 250	$ 250	$ 250	$ 250	$ 250	$ 250
Dividend rate (percent)											5.99%
Per share base redemption value (in Canadian dollars per shares)				$ 25							$ 25	$ 25
Preference Shares, Series 9
Share Capital
Dividend (in Canadian dollars per share)				$ 0.35450	$ 0.25606						$ 1.41800
Preference Shares, Series 9 | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares				11,000,000					11,000,000	11,000,000	11,000,000	11,000,000	11,000,000	11,000,000
Preferred stock, value, outstanding | $				$ 275					$ 275	$ 275	$ 275	$ 275	$ 275	$ 275
Dividend rate (percent)											5.67%
Per share base redemption value (in Canadian dollars per shares)				$ 25							$ 25	$ 25
Preference Shares, Series 11
Share Capital
Dividend (in Canadian dollars per share)											$ 0.98452
Preference Shares, Series 11 | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares				20,000,000					20,000,000	20,000,000	20,000,000	20,000,000	20,000,000	20,000,000
Preferred stock, value, outstanding | $				$ 500					$ 500	$ 500	$ 500	$ 500	$ 500	$ 500
Dividend rate (percent)											3.94%
Per share base redemption value (in Canadian dollars per shares)				$ 25							$ 25	$ 25
Preference Shares, Series 13
Share Capital
Dividend (in Canadian dollars per share)											$ 0.76076
Preference Shares, Series 13 | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares				14,000,000					14,000,000	14,000,000	14,000,000	14,000,000	14,000,000	14,000,000
Preferred stock, value, outstanding | $				$ 350					$ 350	$ 350	$ 350	$ 350	$ 350	$ 350
Dividend rate (percent)											3.04%
Per share base redemption value (in Canadian dollars per shares)				$ 25							$ 25	$ 25
Preference Shares, Series 15
Share Capital
Dividend (in Canadian dollars per share)											$ 0.74576
Preference Shares, Series 15 | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares				11,000,000					11,000,000	11,000,000	11,000,000	11,000,000	11,000,000	11,000,000
Preferred stock, value, outstanding | $				$ 275					$ 275	$ 275	$ 275	$ 275	$ 275	$ 275
Dividend rate (percent)											2.98%
Per share base redemption value (in Canadian dollars per shares)				$ 25							$ 25	$ 25
Preference Shares, Series 19
Share Capital
Dividend (in Canadian dollars per share)											$ 1.55300
Preference Shares, Series 19 | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares				20,000,000					20,000,000	20,000,000	20,000,000	20,000,000	20,000,000	20,000,000
Preferred stock, value, outstanding | $				$ 500					$ 500	$ 500	$ 500	$ 500	$ 500	$ 500
Dividend rate (percent)											6.21%
Per share base redemption value (in Canadian dollars per shares)				$ 25							$ 25	$ 25
Dividend rate reset period (in years)											5 years
Preference Shares, Series 19 | Preferred Shares | Minimum
Share Capital
Dividend rate (percent)											4.90%
Preference Shares, Series E | Preferred Shares | 3-Month Government Of Canada Treasury Bill
Share Capital
Dividend rate -spread on variable rate (percent)				2.40%							2.40%	2.40%
Preference Shares, Series O | Preferred Shares | 3-Month Government Of Canada Treasury Bill
Share Capital
Dividend rate -spread on variable rate (percent)				2.70%							2.70%	2.70%
Preference Shares, Series Q | Preferred Shares | 3-Month Government Of Canada Treasury Bill
Share Capital
Dividend rate -spread on variable rate (percent)				2.50%							2.50%	2.50%
Preference Shares, Series S | Preferred Shares | 3-Month Government Of Canada Treasury Bill
Share Capital
Dividend rate -spread on variable rate (percent)				2.50%							2.50%	2.50%
Preference Shares, Series 4 | Preferred Shares | 3-Month Government Of Canada Treasury Bill
Share Capital
Dividend rate -spread on variable rate (percent)				2.40%							2.40%	2.40%
Preference Shares, Series 8 | Preferred Shares | 3-Month Government Of Canada Treasury Bill
Share Capital
Dividend rate -spread on variable rate (percent)				2.60%							2.60%	2.60%
Preference Shares, Series 10 | Preferred Shares | 3-Month Government Of Canada Treasury Bill
Share Capital
Dividend rate -spread on variable rate (percent)				2.70%							2.70%	2.70%
Preference Shares, Series 12 | Preferred Shares | 3-Month Government Of Canada Treasury Bill
Share Capital
Dividend rate -spread on variable rate (percent)				2.60%							2.60%	2.60%
Preference Shares, Series 14 | Preferred Shares | 3-Month Government Of Canada Treasury Bill
Share Capital
Dividend rate -spread on variable rate (percent)				2.70%							2.70%	2.70%
Preference Shares, Series 16 | Preferred Shares | 3-Month Government Of Canada Treasury Bill
Share Capital
Dividend rate -spread on variable rate (percent)				2.70%							2.70%	2.70%
Preference Shares, Series 20 | Preferred Shares | 3-Month Government Of Canada Treasury Bill
Share Capital
Dividend rate -spread on variable rate (percent)				3.20%							3.20%	3.20%
Preference Shares, Series M | 3-Month Government Of Canada Treasury Bill
Share Capital
Dividend rate -spread on variable rate (percent)				3.20%							3.20%	3.20%
Preference Shares, Series 2 | 3-Month Government Of Canada Treasury Bill
Share Capital
Dividend rate -spread on variable rate (percent)				3.10%							3.10%	3.10%
Preference Shares, Series 6 | 3-Month Government Of Canada Treasury Bill
Share Capital
Dividend rate -spread on variable rate (percent)				2.80%							2.80%	2.80%