STOCKHOLDERS' EQUITY - Dividends (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Class of Stock [Line Items]
Dividends declared per share of common stock (in usd per share)	$ 0.39	$ 0.39
Common stock dividends declared and paid	$ 165	$ 167
Preferred stock dividends declared and paid	$ 24	$ 23
Series A Preferred Stock
Class of Stock [Line Items]
Dividends declared per share of preferred stock (in usd per share)	$ 0	$ 10.49
Series B Preferred Stock
Class of Stock [Line Items]
Dividends declared per share of preferred stock (in usd per share)	0	0
Series C Preferred Stock
Class of Stock [Line Items]
Dividends declared per share of preferred stock (in usd per share)	15.94	15.94
Series D Preferred Stock
Class of Stock [Line Items]
Dividends declared per share of preferred stock (in usd per share)	15.88	15.88
Series E Preferred Stock
Class of Stock [Line Items]
Dividends declared per share of preferred stock (in usd per share)	12.50	12.50
Series F Preferred Stock
Class of Stock [Line Items]
Dividends declared per share of preferred stock (in usd per share)	14.13	14.13
Series G Preferred Stock
Class of Stock [Line Items]
Dividends declared per share of preferred stock (in usd per share)	$ 10.00	$ 0
Dividends Declared
Class of Stock [Line Items]
Common stock dividends declared and paid	$ 165	$ 167
Preferred stock dividends declared and paid	24	23
Dividends Declared | Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared and paid	0	3
Dividends Declared | Series B Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared and paid	0	0
Dividends Declared | Series C Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared and paid	5	5
Dividends Declared | Series D Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared and paid	5	5
Dividends Declared | Series E Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared and paid	5	5
Dividends Declared | Series F Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared and paid	6	5
Dividends Declared | Series G Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared and paid	3	0
Dividends Paid
Class of Stock [Line Items]
Common stock dividends declared and paid	165	167
Preferred stock dividends declared and paid	33	32
Dividends Paid | Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared and paid	0	3
Dividends Paid | Series B Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared and paid	9	9
Dividends Paid | Series C Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared and paid	5	5
Dividends Paid | Series D Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared and paid	5	5
Dividends Paid | Series E Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared and paid	5	5
Dividends Paid | Series F Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared and paid	6	5
Dividends Paid | Series G Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared and paid	$ 3	$ 0