Certain Transfers of Financial Assets and Variable Interest Entities - Additional Information (Detail) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Cash Flows Between Transferor and Transferee, Receipts on Transferor's Interest in Transferred Financial Assets, Other		$ 4	$ 7	$ 8	$ 10
Long-term Debt	[1]	10,109		10,109		$ 13,022
Total liabilities		165,635		165,635		167,323
Assets		188,858		188,858		190,328
LHFS excluded from managed loans disclosure		2,500		2,500		3,200
Trading assets	[2]	6,438		6,438		6,202
Derivative Asset, Fair Value, Gross Asset		5,239		5,239		5,839
Derivative Liability, Fair Value, Gross Liability		5,119		5,119		5,577
Other Assets		5,657		5,657		5,656
Income Tax Credits and Adjustments		15	15	29	30
Amortization of Intangible Assets and Impairment of Goodwill		7	4	13	7
Principal Amount Outstanding on Loans Securitized or Asset-backed Financing Arrangement		1,000		1,000
Proceeds from Securitizations of Consumer Loans		1,000
Affordable Housing Investment [Member]
Gains (Losses) on Sales of Investment Real Estate		(1)		19
Properties sold, carrying value		9		72
Variable Interest Entity, Primary Beneficiary [Member]
Long-term Debt		281		281		302
Residential Mortgage [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Loans and Leases Receivable, Gain (Loss) on Sales, Net		46	61	123	105
Transferor's Interests in Transferred Financial Assets, Fair Value		48		48		55
Assets		266		266		288
Commercial and Corporate Loans [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Total liabilities		590		590		654
Assets		633		633		704
Commercial and Corporate Loans [Member] | Variable Interest Entity, Not Primary Beneficiary [Member] | Preference Shares [Member]
Assets		2		2		3
Commercial and Corporate Loans [Member] | Variable Interest Entity, Not Primary Beneficiary [Member] | Senior Subordinated Notes [Member]
Assets		13		13		18
Student Loans [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Long-term Debt		281		281		302
Loans Receivable, Net		$ 284		$ 284		$ 306
Student Loans [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Maximum [Member]
Government Guarantee Percent		100.00%		100.00%
Total Return Swap | Variable Interest Entity, Not Primary Beneficiary [Member]
Trading assets		$ 2,300		$ 2,300		$ 2,300
Derivative, Notional Amount		2,300		2,300		2,300
Derivative Asset, Fair Value, Gross Asset		17		17		19
Derivative Liability, Fair Value, Gross Liability		13		13		14
Community Development Investments [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Assets		1,800		1,800		1,600
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount		247		247		236
Amortization of Intangible Assets and Impairment of Goodwill		5	3	10	5
Real Estate Variable Interest Entity Borrowings		127		127		113
Limited Partner [Member] | Community Development Investments [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Other Assets		477		477		363
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount		959		959		910
Loans issued by the Company to the limited partnerships		389		389		$ 412
provision for income taxes [Member]
Other Depreciation and Amortization		$ 14	$ 14	28	$ 27
Affordable Housing [Member]
Gains (Losses) on Sales of Investment Real Estate				$ (19)

[1] Includes debt of consolidated VIEs of $281 million and $302 million at June 30, 2015 and December 31, 2014, respectively.

[2] Includes trading securities pledged as collateral where counterparties have the right to sell or repledge the collateral of $1,481 million and $1,316 million at June 30, 2015 and December 31, 2014, respectively