Stock-Based Compensation Expense Recognized in Noninterest Expense (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stock-based compensation expense:
Stock or Unit Option Plan Expense	$ 1	$ 2	$ 6
Restricted Stock or Unit Expense	16	27	32
Phantom Stock Units	32	13	0
Restricted Stock Units Expense	46	34	18
Share-based Compensation	95	76	56
Employee Service Share-based Compensation, Tax Benefit Realized from Exercise of Stock Options	$ 36	$ 29	$ 21