STOCKHOLDERS' EQUITY - Dividends (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Class of Stock [Line Items]
Dividends declared per share of common stock (in usd per share)	$ 1.56	$ 1.56	$ 1.36
Common stock dividends declared and paid	$ 670	$ 672	$ 617
Preferred stock dividends declared and paid	113	107	73
Dividends Declared
Class of Stock [Line Items]
Common stock dividends declared and paid	670	672	617
Preferred stock dividends declared and paid	113	107	73
Dividends Paid
Class of Stock [Line Items]
Common stock dividends declared and paid	670	672	617
Preferred stock dividends declared and paid	$ 113	$ 98	$ 65
Series A
Class of Stock [Line Items]
Dividends declared per share of preferred stock (in usd per share)	$ 20.99	$ 62.59	$ 55.00
Series A | Dividends Declared
Class of Stock [Line Items]
Preferred stock dividends declared and paid	$ 5	$ 15	$ 14
Series A | Dividends Paid
Class of Stock [Line Items]
Preferred stock dividends declared and paid	$ 8	$ 13	$ 14
Series B
Class of Stock [Line Items]
Dividends declared per share of preferred stock (in usd per share)	$ 60.00	$ 60.00	$ 60.00
Series B | Dividends Declared
Class of Stock [Line Items]
Preferred stock dividends declared and paid	$ 18	$ 18	$ 18
Series B | Dividends Paid
Class of Stock [Line Items]
Preferred stock dividends declared and paid	$ 18	$ 18	$ 20
Series C
Class of Stock [Line Items]
Dividends declared per share of preferred stock (in usd per share)	$ 63.75	$ 63.75	$ 63.75
Series C | Dividends Declared
Class of Stock [Line Items]
Preferred stock dividends declared and paid	$ 19	$ 19	$ 19
Series C | Dividends Paid
Class of Stock [Line Items]
Preferred stock dividends declared and paid	$ 19	$ 19	$ 18
Series D
Class of Stock [Line Items]
Dividends declared per share of preferred stock (in usd per share)	$ 63.50	$ 63.50	$ 59.45
Series D | Dividends Declared
Class of Stock [Line Items]
Preferred stock dividends declared and paid	$ 18	$ 19	$ 18
Series D | Dividends Paid
Class of Stock [Line Items]
Preferred stock dividends declared and paid	$ 18	$ 19	$ 13
Series E
Class of Stock [Line Items]
Dividends declared per share of preferred stock (in usd per share)	$ 50.00	$ 50.00	$ 9.44
Series E | Dividends Declared
Class of Stock [Line Items]
Preferred stock dividends declared and paid	$ 23	$ 23	$ 4
Series E | Dividends Paid
Class of Stock [Line Items]
Preferred stock dividends declared and paid	$ 23	$ 21	$ 0
Series F
Class of Stock [Line Items]
Dividends declared per share of preferred stock (in usd per share)	$ 56.50	$ 33.27	$ 0
Series F | Dividends Declared
Class of Stock [Line Items]
Preferred stock dividends declared and paid	$ 23	$ 13	$ 0
Series F | Dividends Paid
Class of Stock [Line Items]
Preferred stock dividends declared and paid	$ 23	$ 8	$ 0
Series G
Class of Stock [Line Items]
Dividends declared per share of preferred stock (in usd per share)	$ 22.78	$ 0	$ 0
Series G | Dividends Declared
Class of Stock [Line Items]
Preferred stock dividends declared and paid	$ 7	$ 0	$ 0
Series G | Dividends Paid
Class of Stock [Line Items]
Preferred stock dividends declared and paid	$ 4	$ 0	$ 0