STOCKHOLDERS' EQUITY - Preferred Stock Narrative (Details) - USD ($)		1 Months Ended
	Jun. 11, 2021	Jun. 30, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Preferred stock, value, issued		$ 2,014,000,000	$ 1,965,000,000
Preferred stock, issued (in shares)		2,050,000	2,000,000
Preferred stock, par value (in dollars per share)		$ 25.00	$ 25.00
US Treasury (UST) Interest Rate, Five-Year
Class of Stock [Line Items]
Preferred stock, dividend payment rate, basis spread on variable rate	3.215%
Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock, value, issued		$ 0	$ 247,000,000
Preferred stock, issued (in shares)		0	250,000
Preferred stock, dividend rate		5.50%
Preferred stock, liquidation preference per share (in dollars per share)		$ 1,000
Series G Preferred Stock
Class of Stock [Line Items]
Preferred stock, value, issued	$ 300,000,000	$ 296,000,000	$ 0
Preferred stock, issued (in shares)		300,000	0
Preferred stock, dividend rate	4.00%
Preferred stock, par value (in dollars per share)	$ 25.00
Preferred stock, liquidation preference per share (in dollars per share)	$ 1,000
Proceeds from issuance of stock	$ 296,000,000
Redemption notice period	90 days
Redemption price per share (usd per share)	$ 1,000