EARNINGS PER COMMON SHARE COMPUTATION (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income available for common stockholders	$ 1,531	$ 1,340	$ 2,947	$ 3,641
Weighted average outstanding shares of common stock used to compute basic earnings per common share (in shares)	128,518	132,318	128,714	132,234
Shares used to compute diluted earnings per common share (in shares)	129,255	133,196	129,398	133,010
Basic earnings per common share (in dollars per share)	$ 11.91	$ 10.12	$ 22.90	$ 27.53
Diluted earnings per common share (in dollars per share)	$ 11.84	$ 10.05	$ 22.77	$ 27.37
Number of antidilutive stock options and restricted stock excluded from computation (in shares)	136	143	256	311
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)	68	105	65	95
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)	669	773	619	681