EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Numerator (basic and diluted):
Net income	$ 453	$ 425	$ 892	$ 813
Less: Preferred stock dividends	18	0	33	7
Net income available to common stockholders	$ 435	$ 425	$ 859	$ 806
Denominator:
Weighted-average common shares outstanding - basic (in shares)	458,154,335	484,744,354	459,426,685	486,114,872
Dilutive common shares: share-based awards (in shares)	1,149,889	1,397,341	1,430,850	1,568,344
Weighted-average common shares outstanding - diluted (in shares)	459,304,224	486,141,695	460,857,535	487,683,216
Earnings per common share:
Basic (in dollars per share)	$ 0.95	$ 0.88	$ 1.87	$ 1.66
Diluted (in dollars per share)	$ 0.95	$ 0.88	$ 1.86	$ 1.65
Share-based awards excluded from diluted earnings per share computation (in shares)	371,627	0	1,073,431