EARNINGS PER COMMON SHARE COMPUTATION (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income available for common stockholders	$ 473	$ 566
Weighted average outstanding shares of common stock used to compute basic earnings per common share (in shares)	132,135	135,383
Shares used to compute diluted earnings per common share (in shares)	132,811	135,962
Basic earnings per common share (in dollars per share)	$ 3.58	$ 4.18
Diluted earnings per common share (in dollars per share)	$ 3.56	$ 4.16
Number of antidilutive stock options and restricted stock excluded from computation (in shares)	660	703
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)	92	130
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)	584	449