EARNINGS PER COMMON SHARE COMPUTATION (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income available for common stockholders	$ 588	$ 1,828	$ 1,416	$ 2,301
Weighted average outstanding shares of common stock used to compute basic earnings per common share (in shares)	128,692	132,248	128,811	132,192
Shares used to compute diluted earnings per common share (in shares)	129,387	133,023	129,469	132,917
Basic earnings per common share (in dollars per share)	$ 4.57	$ 13.83	$ 11.00	$ 17.41
Diluted earnings per common share (in dollars per share)	$ 4.55	$ 13.75	$ 10.94	$ 17.31
Number of antidilutive stock options and restricted stock excluded from computation (in shares)	103	130	317	395
Employee stock options
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Dilutive effect of employee stock options and restricted stock (in shares)	74	89	63	90
Restricted stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Dilutive effect of employee stock options and restricted stock (in shares)	621	686	595	635