EARNINGS PER COMMON SHARE COMPUTATION (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income available for common stockholders	$ 828	$ 473
Weighted average outstanding shares of common stock used to compute basic earnings per common share (in shares)	128,931	132,135
Shares used to compute diluted earnings per common share (in shares)	129,551	132,811
Basic earnings per common share (in dollars per share)	$ 6.42	$ 3.58
Diluted earnings per common share (in dollars per share)	$ 6.39	$ 3.56
Number of antidilutive stock options and restricted stock excluded from computation (in shares)	531	660
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)	52	92
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)	568	584