Asset Transfers in Which the Company has Continuing Economic Involvement (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1]	$ 2,091		$ 2,091		$ 2,579
Cash flows on interests held		(6)	$ (2)	(14)	$ (14)
Other Noninterest Expense		95	83	286	333
Amortization		9	7	22	14
Community Development Investments [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Real Estate Variable Interest Entity Borrowings		130		130		113
Residential Mortgage [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Loans and Leases Receivable, Gain (Loss) on Sales, Net		48	$ 50	171	$ 155
Transferor's Interests in Transferred Financial Assets, Fair Value		43		43		55
Affordable Housing [Member]
Gains (Losses) on Sales of Investment Real Estate		0		(19)
Affordable Housing Investment [Member]
Properties sold, carrying value				72
Gains (Losses) on Sales of Investment Real Estate				19
Residential Portfolio Segment [Member]
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1]	$ 703		$ 703		$ 891

[1] Excludes $1 million and $39 million of past due LHFS at September 30, 2015 and December 31, 2014, respectively.