SHARE CAPITAL - PREFERRED SHARES (Details) $ / shares in Units, shares in Millions, $ in Millions							12 Months Ended
	Dec. 01, 2021 $ / shares	Sep. 01, 2021 $ / shares	Jun. 01, 2021 $ / shares	Mar. 01, 2021 $ / shares	Feb. 28, 2021 $ / shares	Mar. 20, 2019 $ / shares	Dec. 31, 2021 CAD ($) $ / shares shares	Dec. 31, 2021 CAD ($) $ / shares $ / shares shares	Dec. 31, 2020 CAD ($) shares	Dec. 31, 2019 CAD ($) shares	Dec. 31, 2021 $ / shares
Preferred Shares
Share Capital
Preferred stock, value, outstanding | $							$ 7,747	$ 7,747	$ 7,747	$ 7,747
Issuance costs | $							$ (155)		$ (155)	$ (155)
Recurring anniversary period following the redemption option date, at which the entity may redeem preferred shares							5 years
Stock split conversion ratio							1
Quarterly floating rate cumulative dividends per share calculation, base multiplier (in dollars per share) | (per share)							$ 25	$ 25
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							18	18	18	18
Preferred stock, value, outstanding | $							$ 457	$ 457	$ 457	$ 457
Initial Yield (as a percent)							3.42%
Yearly dividend per share (in dollars per share)							$ 0.85360
Per Share Base Redemption Value (in dollars per shares)							$ 25	$ 25
Preference Shares, Series C
Share Capital
Yearly dividend per share (in dollars per share)	$ 0.15719	$ 0.16081	$ 0.15753	$ 0.15501	$ 0.15349
Preference Shares, Series C | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares							2	2	2	2
Preferred stock, value, outstanding | $							$ 43	$ 43	$ 43	$ 43
Yearly dividend per share (in dollars per share)							$ 0
Per Share Base Redemption Value (in dollars per shares)							$ 25	$ 25
Quarterly floating rate cumulative dividends per share calculation, spread on Government of Canada treasury bill rate (as a percent)							2.40%
Preference Shares, Series C | US Treasury Rate | Preferred Shares
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
Preference Shares, Series J | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares							8	8	8	8
Preferred stock, value, outstanding | $							$ 199	$ 199	$ 199	$ 199
Initial Yield (as a percent)							4.89%
Yearly dividend per share (in dollars per share)								$ 1.22160
Per Share Base Redemption Value (in dollars per shares)											$ 25
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)							4.96%
Yearly dividend per share (in dollars per share)								$ 1.23972
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)						5.50%	4.45%
Yearly dividend per share (in dollars per share)							$ 1.11224
Per Share Base Redemption Value (in dollars per shares)						$ 25	$ 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
Preference Shares, Series 17 | Preferred Shares
Share Capital
Preferred stock, shares outstanding (in shares) | shares							30	30	30	30
Preferred stock, value, outstanding | $							$ 750	$ 750	$ 750	$ 750
Initial Yield (as a percent)							5.15%
Yearly dividend per share (in dollars per share)							$ 1.28750
Per Share Base Redemption Value (in dollars per shares)							$ 25	$ 25
Minimum fixed dividend rate upon reset (as a percent)							5.15%
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
Minimum fixed dividend rate upon reset (as a percent)							4.90%
Preferred Stock Excluding Series | Preferred Shares
Share Capital
Reset term of fixed dividend rate							5 years
Preference Shares, Series E | Preferred Shares
Share Capital
Quarterly floating rate cumulative dividends per share calculation, spread on Government of Canada treasury bill rate (as a percent)							2.40%
Series G Preferred Stock | Preferred Shares
Share Capital
Quarterly floating rate cumulative dividends per share calculation, spread on Government of Canada treasury bill rate (as a percent)							2.50%
Series I Preferred Stock | Preferred Shares
Share Capital
Quarterly floating rate cumulative dividends per share calculation, spread on Government of Canada treasury bill rate (as a percent)							2.10%
Series O Preferred Stock | Preferred Shares
Share Capital
Quarterly floating rate cumulative dividends per share calculation, spread on Government of Canada treasury bill rate (as a percent)							2.70%
Series Q Preferred Stock | Preferred Shares
Share Capital
Quarterly floating rate cumulative dividends per share calculation, spread on Government of Canada treasury bill rate (as a percent)							2.50%
Series S Preferred Stock | Preferred Shares
Share Capital
Quarterly floating rate cumulative dividends per share calculation, spread on Government of Canada treasury bill rate (as a percent)							2.50%
Series 4 Preferred Stock | Preferred Shares
Share Capital
Quarterly floating rate cumulative dividends per share calculation, spread on Government of Canada treasury bill rate (as a percent)							2.40%
Series 8 Preferred Stock | Preferred Shares
Share Capital
Initial Yield (as a percent)						5.60%
Per Share Base Redemption Value (in dollars per shares)						$ 25
Quarterly floating rate cumulative dividends per share calculation, spread on Government of Canada treasury bill rate (as a percent)							2.60%
Series10 Preferred Stock | Preferred Shares
Share Capital
Quarterly floating rate cumulative dividends per share calculation, spread on Government of Canada treasury bill rate (as a percent)							2.70%
Series12 Preferred Stock | Preferred Shares
Share Capital
Quarterly floating rate cumulative dividends per share calculation, spread on Government of Canada treasury bill rate (as a percent)							2.60%
Series14 Preferred Stock | Preferred Shares
Share Capital
Quarterly floating rate cumulative dividends per share calculation, spread on Government of Canada treasury bill rate (as a percent)							2.70%
Series16 Preferred Stock | Preferred Shares
Share Capital
Quarterly floating rate cumulative dividends per share calculation, spread on Government of Canada treasury bill rate (as a percent)							2.70%
Series18 Preferred Stock | Preferred Shares
Share Capital
Quarterly floating rate cumulative dividends per share calculation, spread on Government of Canada treasury bill rate (as a percent)							4.10%
Series 20 Preferred Stock | Preferred Shares
Share Capital
Quarterly floating rate cumulative dividends per share calculation, spread on Government of Canada treasury bill rate (as a percent)							3.20%
Series K Preferred Stock | Preferred Shares
Share Capital
Quarterly floating rate cumulative dividends per share calculation, spread on Government of US treasury bill rate (as a percent)							3.10%
Series M Preferred Stock | Preferred Shares
Share Capital
Quarterly floating rate cumulative dividends per share calculation, spread on Government of US treasury bill rate (as a percent)							3.20%
Series 2 Preferred Stock | Preferred Shares
Share Capital
Quarterly floating rate cumulative dividends per share calculation, spread on Government of US treasury bill rate (as a percent)							3.10%
Series 6 Preferred Stock | Preferred Shares
Share Capital
Quarterly floating rate cumulative dividends per share calculation, spread on Government of US treasury bill rate (as a percent)							2.80%