EARNINGS PER COMMON SHARE COMPUTATION (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income available for common stockholders	$ 193	$ 650	$ 684	$ 1,765
Weighted average outstanding shares of common stock used to compute basic earnings per common share (in shares)	137,763	144,600	137,833	146,212
Shares used to compute diluted earnings per common share (in shares)	138,576	145,634	138,703	147,253
Basic earnings per common share (in dollars per share)	$ 1.40	$ 4.49	$ 4.96	$ 12.07
Diluted earnings per common share (in dollars per share)	$ 1.39	$ 4.46	$ 4.93	$ 11.98
Number of antidilutive stock options and restricted stock excluded from computation (in shares)	171	449	408	693
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)	197	158	205	179
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)	616	876	665	862