SHARE CAPITAL - Preferred Shares (Details) $ / shares in Units, $ / shares in Units, shares in Millions, $ in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2022 CAD ($) $ / shares shares	Dec. 31, 2022 CAD ($) $ / shares $ / shares shares	Dec. 31, 2021 CAD ($) shares	Dec. 31, 2020 CAD ($) shares	Dec. 31, 2022 $ / shares	Jun. 01, 2022 USD ($)	Mar. 01, 2022 CAD ($)
Preferred Shares
Share Capital
Preferred stock, value, outstanding | $	$ 6,818	$ 6,818	$ 7,747	$ 7,747
Issuance costs | $	$ (135)		$ (155)	$ (155)
Preference Shares, Series A | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares	5	5	5	5
Preferred stock, value, outstanding | $	$ 125	$ 125	$ 125	$ 125
Initial Yield (as a percent)	5.50%
Yearly dividend per share (in dollars per share)	$ 1.37500
Per Share Base Redemption Value (in dollars per shares)	$ 25	$ 25
Preference Shares, Series B | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares	20	20	18	18
Preferred stock, value, outstanding | $	$ 500	$ 500	$ 457	$ 457
Initial Yield (as a percent)	5.20%
Yearly dividend per share (in dollars per share)	$ 1.30052
Per Share Base Redemption Value (in dollars per shares)	$ 25	$ 25
Preference Shares, Series C1 | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares	0	0	2	2
Preferred stock, value, outstanding | $	$ 0	$ 0	$ 43	$ 43
Preference Shares, Series C1 | Preferred Shares | US Treasury Rate
Share Capital
Initial yield, spread on variable rate (percent)	2.40%	2.40%
Preference Shares, Series D | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares	18	18	18	18
Preferred stock, value, outstanding | $	$ 450	$ 450	$ 450	$ 450
Initial Yield (as a percent)	4.46%
Yearly dividend per share (in dollars per share)	$ 1.11500
Per Share Base Redemption Value (in dollars per shares)	$ 25	$ 25
Preference Shares, Series F | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares	20	20	20	20
Preferred stock, value, outstanding | $	$ 500	$ 500	$ 500	$ 500
Initial Yield (as a percent)	4.69%
Yearly dividend per share (in dollars per share)	$ 1.17224
Per Share Base Redemption Value (in dollars per shares)	$ 25	$ 25
Preference Shares, Series H | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares	14	14	14	14
Preferred stock, value, outstanding | $	$ 350	$ 350	$ 350	$ 350
Initial Yield (as a percent)	4.38%
Yearly dividend per share (in dollars per share)	$ 1.09400
Per Share Base Redemption Value (in dollars per shares)	$ 25	$ 25
Series J Preferred Stock
Share Capital
Preferred stock, redemption amount | $						$ 200
Series J Preferred Stock | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares	0	0	8	8
Preferred stock, value, outstanding | $	$ 0	$ 0	$ 199	$ 199
Preference Shares, Series L | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares	16	16	16	16
Preferred stock, value, outstanding | $	$ 411	$ 411	$ 411	$ 411
Initial Yield (as a percent)	5.86%
Yearly dividend per share (in dollars per share)		$ 1.46448
Per Share Base Redemption Value (in dollars per shares)					$ 25
Preference Shares, Series N | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares	18	18	18	18
Preferred stock, value, outstanding | $	$ 450	$ 450	$ 450	$ 450
Initial Yield (as a percent)	5.09%
Yearly dividend per share (in dollars per share)	$ 1.27152
Per Share Base Redemption Value (in dollars per shares)	$ 25	$ 25
Preference Shares, Series P | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares	16	16	16	16
Preferred stock, value, outstanding | $	$ 400	$ 400	$ 400	$ 400
Initial Yield (as a percent)	4.38%
Yearly dividend per share (in dollars per share)	$ 1.09476
Per Share Base Redemption Value (in dollars per shares)	$ 25	$ 25
Preference Shares, Series R | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares	16	16	16	16
Preferred stock, value, outstanding | $	$ 400	$ 400	$ 400	$ 400
Initial Yield (as a percent)	4.07%
Yearly dividend per share (in dollars per share)	$ 1.01825
Per Share Base Redemption Value (in dollars per shares)	$ 25	$ 25
Preference Shares, Series 1 | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares	16	16	16	16
Preferred stock, value, outstanding | $	$ 411	$ 411	$ 411	$ 411
Initial Yield (as a percent)	5.95%
Yearly dividend per share (in dollars per share)		$ 1.48728
Per Share Base Redemption Value (in dollars per shares)					25
Preference Shares, Series 3 | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares	24	24	24	24
Preferred stock, value, outstanding | $	$ 600	$ 600	$ 600	$ 600
Initial Yield (as a percent)	3.74%
Yearly dividend per share (in dollars per share)	$ 0.93425
Per Share Base Redemption Value (in dollars per shares)	$ 25	$ 25
Preference Shares, Series 5 | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares	8	8	8	8
Preferred stock, value, outstanding | $	$ 206	$ 206	$ 206	$ 206
Initial Yield (as a percent)	5.38%
Yearly dividend per share (in dollars per share)		$ 1.34383
Per Share Base Redemption Value (in dollars per shares)					$ 25
Preference Shares, Series 7 | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares	10	10	10	10
Preferred stock, value, outstanding | $	$ 250	$ 250	$ 250	$ 250
Initial Yield (as a percent)	4.45%
Yearly dividend per share (in dollars per share)	$ 1.11224
Per Share Base Redemption Value (in dollars per shares)	$ 25	$ 25
Preference Shares, Series 9 | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares	11	11	11	11
Preferred stock, value, outstanding | $	$ 275	$ 275	$ 275	$ 275
Initial Yield (as a percent)	4.10%
Yearly dividend per share (in dollars per share)	$ 1.02424
Per Share Base Redemption Value (in dollars per shares)	$ 25	$ 25
Preference Shares, Series 11 | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares	20	20	20	20
Preferred stock, value, outstanding | $	$ 500	$ 500	$ 500	$ 500
Initial Yield (as a percent)	3.94%
Yearly dividend per share (in dollars per share)	$ 0.98452
Per Share Base Redemption Value (in dollars per shares)	$ 25	$ 25
Preference Shares, Series 13 | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares	14	14	14	14
Preferred stock, value, outstanding | $	$ 350	$ 350	$ 350	$ 350
Initial Yield (as a percent)	3.04%
Yearly dividend per share (in dollars per share)	$ 0.76076
Per Share Base Redemption Value (in dollars per shares)	$ 25	$ 25
Preference Shares, Series 15 | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares	11	11	11	11
Preferred stock, value, outstanding | $	$ 275	$ 275	$ 275	$ 275
Initial Yield (as a percent)	2.98%
Yearly dividend per share (in dollars per share)	$ 0.74576
Per Share Base Redemption Value (in dollars per shares)	$ 25	$ 25
Series17 Preferred Stock
Share Capital
Preferred stock, redemption amount | $							$ 750
Series17 Preferred Stock | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares	0	0	30	30
Preferred stock, value, outstanding | $	$ 0	$ 0	$ 750	$ 750
Preference Shares, Series 19 | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares	20	20	20	20
Preferred stock, value, outstanding | $	$ 500	$ 500	$ 500	$ 500
Initial Yield (as a percent)	4.90%
Yearly dividend per share (in dollars per share)	$ 1.22500
Per Share Base Redemption Value (in dollars per shares)	$ 25	$ 25