Stock-Based Compensation Expense Recognized in Noninterest Expense (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stock-based compensation expense:
Stock or Unit Option Plan Expense		$ 0	$ 1	$ 2
Restricted Stock or Unit Expense		2	16	27
Performance Stock Units	[1]	67	32	13
Restricted Stock Unit Expense		56	46	34
Share-based Compensation		125	95	76
Employee Service Share-based Compensation, Tax Benefit Realized from Exercise of Stock Options		$ 48	$ 36	$ 29

[1] Phantom stock units are settled in cash.