EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator (basic and diluted):
Net income	$ 314	$ 449	$ 601	$ 1,341
Less: Preferred stock dividends	25	17	75	50
Net income available to common stockholders	$ 289	$ 432	$ 526	$ 1,291
Denominator:
Weighted-average common shares outstanding - basic (in shares)	426,846,096	445,703,987	427,058,412	454,802,186
Dilutive common shares: share-based awards (in shares)	1,146,253	1,430,608	1,083,946	1,416,569
Weighted-average common shares outstanding - diluted (in shares)	427,992,349	447,134,595	428,142,358	456,218,755
Earnings per common share:
Basic (in dollars per share)	$ 0.68	$ 0.97	$ 1.23	$ 2.84
Diluted (in dollars per share)	$ 0.68	$ 0.97	$ 1.23	$ 2.83
Share-based awards excluded from diluted earnings per share computation (in shares)	1,193,668	772	1,249,785	359,952