PREFERRED STOCK - Schedule of Preferred Stock Outstanding (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Class of Stock [Line Items]
Carrying value	$ 17,600	$ 17,600
Series D
Class of Stock [Line Items]
Redemption price per depositary share/ preference share (in dollars per share)	$ 1,000
Number of depositary shares (in shares)	1,250,000
Carrying value	$ 1,250	1,250
Series D | SOFR
Class of Stock [Line Items]
Dividend rate (as a percent)	3.72761%
Series D | LIBOR
Class of Stock [Line Items]
Dividend rate (as a percent)	0.26161%
Series J
Class of Stock [Line Items]
Redemption price per depositary share/ preference share (in dollars per share)	$ 25
Number of depositary shares (in shares)	22,000,000
Carrying value	$ 0	550
Series M
Class of Stock [Line Items]
Dividend rate (as a percent)	6.30%
Redemption price per depositary share/ preference share (in dollars per share)	$ 1,000
Number of depositary shares (in shares)	1,750,000
Carrying value	$ 1,750	1,750
Series P
Class of Stock [Line Items]
Dividend rate (as a percent)	5.95%
Redemption price per depositary share/ preference share (in dollars per share)	$ 1,000
Number of depositary shares (in shares)	2,000,000
Carrying value	$ 2,000	2,000
Series T
Class of Stock [Line Items]
Dividend rate (as a percent)	6.25%
Redemption price per depositary share/ preference share (in dollars per share)	$ 1,000
Number of depositary shares (in shares)	1,500,000
Carrying value	$ 1,500	1,500
Series U
Class of Stock [Line Items]
Dividend rate (as a percent)	5.00%
Redemption price per depositary share/ preference share (in dollars per share)	$ 1,000
Number of depositary shares (in shares)	1,500,000
Carrying value	$ 1,500	1,500
Series V
Class of Stock [Line Items]
Dividend rate (as a percent)	4.70%
Redemption price per depositary share/ preference share (in dollars per share)	$ 1,000
Number of depositary shares (in shares)	1,500,000
Carrying value	$ 1,500	1,500
Series W
Class of Stock [Line Items]
Dividend rate (as a percent)	4.00%
Redemption price per depositary share/ preference share (in dollars per share)	$ 1,000
Number of depositary shares (in shares)	1,500,000
Carrying value	$ 1,500	1,500
Series X
Class of Stock [Line Items]
Dividend rate (as a percent)	3.875%
Redemption price per depositary share/ preference share (in dollars per share)	$ 1,000
Number of depositary shares (in shares)	2,300,000
Carrying value	$ 2,300	2,300
Series Y
Class of Stock [Line Items]
Dividend rate (as a percent)	4.15%
Redemption price per depositary share/ preference share (in dollars per share)	$ 1,000
Number of depositary shares (in shares)	1,000,000
Carrying value	$ 1,000	1,000
Series Z
Class of Stock [Line Items]
Dividend rate (as a percent)	7.375%
Redemption price per depositary share/ preference share (in dollars per share)	$ 1,000
Number of depositary shares (in shares)	1,250,000
Carrying value	$ 1,250	1,250
Series AA
Class of Stock [Line Items]
Dividend rate (as a percent)	7.625%
Redemption price per depositary share/ preference share (in dollars per share)	$ 1,000
Number of depositary shares (in shares)	1,500,000
Carrying value	$ 1,500	1,500
Series BB
Class of Stock [Line Items]
Dividend rate (as a percent)	7.20%
Redemption price per depositary share/ preference share (in dollars per share)	$ 1,000
Number of depositary shares (in shares)	550,000
Carrying value	$ 550	$ 0