EARNINGS PER COMMON SHARE COMPUTATION (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income available for common stockholders	$ 499	$ 450	$ 2,264	$ 1,015
Weighted average outstanding shares of common stock used to compute basic earnings per common share (in shares)	144,215	149,417	145,546	149,321
Shares used to compute diluted earnings per common share (in shares)	145,360	150,904	146,622	150,869
Basic earnings per common share (in dollars per share)	$ 3.46	$ 3.01	$ 15.56	$ 6.80
Diluted earnings per common share (in dollars per share)	$ 3.44	$ 2.98	$ 15.44	$ 6.73
Number of antidilutive stock options and restricted stock excluded from computation (in shares)	399	658	595	873
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)	165	210	174	216
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)	980	1,277	902	1,332