Stock-Based Compensation Expense Recognized in Noninterest Expense (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Restricted Stock or Unit Expense		$ 21	$ 14	$ 82	$ 64
Performance Stock Units Expense	[1]	10	17	36	57
Share-based Compensation		31	31	118	121
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	[2]	$ 8	$ 12	$ 28	$ 46

[1] Phantom stock units are settled in cash. During the three and nine months ended September 30, 2018, the Company paid $1 million and $76 million, respectively, related to these share-based liabilities. During the three and nine months ended September 30, 2017, the Company paid $2 million and $79 million, respectively, related to these share-based liabilities.

[2] Does not include excess tax benefits or deficiencies recognized in the Provision for income taxes in the Consolidated Statements of Income.