STOCKHOLDERS' EQUITY - Preferred Stock (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Jun. 11, 2021	Dec. 31, 2020
Preferred Stock
Preferred stock, authorized (in shares)	100,000,000		100,000,000
Preferred stock, par value (in dollars per share)	$ 25.00		$ 25.00
Preferred stock, issued (in shares)	2,050,000		2,000,000
Preferred stock, issued	$ 2,014,000,000		$ 1,965,000,000
Preferred stock, outstanding (in shares)	2,050,000		2,000,000
Preferred stock, outstanding	$ 2,014,000,000		$ 1,965,000,000
Series A
Preferred Stock
Preferred stock, liquidation preference (in dollars per share)	$ 1,000
Preferred stock, issued (in shares)	0		250,000
Preferred stock, issued	$ 0		$ 247,000,000
Preferred stock, outstanding (in shares)	0		250,000
Preferred stock, outstanding	$ 0		$ 247,000,000
Series B
Preferred Stock
Preferred stock, liquidation preference (in dollars per share)	$ 1,000
Preferred stock, issued (in shares)	300,000		300,000
Preferred stock, issued	$ 296,000,000		$ 296,000,000
Preferred stock, outstanding (in shares)	300,000		300,000
Preferred stock, outstanding	$ 296,000,000		$ 296,000,000
Series C
Preferred Stock
Preferred stock, liquidation preference (in dollars per share)	$ 1,000
Preferred stock, issued (in shares)	300,000		300,000
Preferred stock, issued	$ 297,000,000		$ 297,000,000
Preferred stock, outstanding (in shares)	300,000		300,000
Preferred stock, outstanding	$ 297,000,000		$ 297,000,000
Series D
Preferred Stock
Preferred stock, liquidation preference (in dollars per share)	$ 1,000
Preferred stock, issued (in shares)	300,000		300,000
Preferred stock, issued	$ 293,000,000		$ 293,000,000
Preferred stock, outstanding (in shares)	300,000		300,000
Preferred stock, outstanding	$ 293,000,000		$ 293,000,000
Shares issued (in dollars per share)	$ 25
Depositary shares issued (in shares)	12,000,000
Depository share interest percentage	2.50%
Series E
Preferred Stock
Preferred stock, liquidation preference (in dollars per share)	$ 1,000
Preferred stock, issued (in shares)	450,000		450,000
Preferred stock, issued	$ 437,000,000		$ 437,000,000
Preferred stock, outstanding (in shares)	450,000		450,000
Preferred stock, outstanding	$ 437,000,000		$ 437,000,000
Shares issued (in dollars per share)	$ 25
Depositary shares issued (in shares)	18,000,000
Depository share interest percentage	2.50%
Series F
Preferred Stock
Preferred stock, liquidation preference (in dollars per share)	$ 1,000
Preferred stock, issued (in shares)	400,000		400,000
Preferred stock, issued	$ 395,000,000		$ 395,000,000
Preferred stock, outstanding (in shares)	400,000		400,000
Preferred stock, outstanding	$ 395,000,000		$ 395,000,000
Series G
Preferred Stock
Preferred stock, par value (in dollars per share)	$ 25
Preferred stock, liquidation preference (in dollars per share)	$ 1,000
Preferred stock, issued (in shares)	300,000	300,000	0
Preferred stock, issued	$ 296,000,000	$ 300,000,000	$ 0
Preferred stock, outstanding (in shares)	300,000		0
Preferred stock, outstanding	$ 296,000,000		$ 0