Fair Value Measurement and Election - Additional Information (Detail) (USD $)	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Assets	$ 182,559,000,000			$ 182,559,000,000		$ 175,335,000,000
Transfer of Loans Held-for-sale to Portfolio Loans	3,000,000		5,000,000	20,000,000	17,000,000
Loans Receivable, Fair Value Disclosure	292,000,000			292,000,000		302,000,000
Allowance for Loan and Lease Losses, Write-offs	(158,000,000)		(233,000,000)	(309,000,000)	(506,000,000)
Loans held for investment sold	534,000,000		159,000,000	619,000,000	662,000,000
Gain (Loss) on Sales of Loans, Net	22,000,000		3,000,000	31,000,000	7,000,000
Unfunded loan commitments and letters of credit	53,000,000,000			53,000,000,000		48,900,000,000
Allowance for unfunded loan commitments and letters of credit	45,000,000			45,000,000		53,000,000
Total Return Swap | Fair Value, Inputs, Level 2 [Member]
Loans Receivable, Fair Value Disclosure	1,400,000,000			1,400,000,000		1,500,000,000
Interest Rate Lock Commitments [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	60,000,000		72,000,000	118,000,000	207,000,000
Asset-backed Securities [Member] | Student Loans [Member]
Government guaranteed percent						97.00%
Trading Account Assets [Member] | Commercial and Corporate Leveraged Loans [Member] | Fair Value, Inputs, Level 2 [Member]
Loans Receivable, Fair Value Disclosure	321,000,000			321,000,000		313,000,000
Fair Value, Option, Credit Risk, Gains (Losses) on Assets	1,000,000		1,000,000	2,000,000	2,000,000
Residential Mortgage, Loans Held For Sale [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Option, Credit Risk, Gains (Losses) on Assets			2,000,000	1,000,000	(2,000,000)
Residential Mortgage, Loans Held For Sale [Member] | Nonperforming Financing Receivable [Member]
Loans held for investment sold						39,000,000
Collateralized Loan Obligations [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Option, Credit Risk, Gains (Losses) on Assets	0		(1,000,000)	0	1,000,000
Long-term Debt [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Option, Credit Risk, Gains (Losses) on Liabilities	11,000,000		(1,000,000)	27,000,000	(19,000,000)
Loans Held For Sale [Member] | Nonperforming Financing Receivable [Member]
Transfer Of Portfolio Loans And Leases To Held For Sale Net Of Impairment						22,000,000
Loans sold at carrying value				10,000,000
Loans Held For Sale [Member] | Residential Portfolio Segment [Member]
Gain (Loss) on Sales of Loans, Net					5,000,000
Loans Held For Sale [Member] | Nonperforming Residential Mortgages Transferred To Held For Sale During Period [Member]
Allowance for Loan and Lease Losses, Write-offs					(3,000,000)
Commercial and Corporate Loans [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Assets	800,000,000			800,000,000		1,600,000,000
Commercial and Corporate Loans [Member] | Variable Interest Entity, Not Primary Beneficiary [Member] | Preference Shares [Member]
Assets	5,000,000			5,000,000		3,000,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Loans Receivable, Fair Value Disclosure	0			0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Loans Receivable, Fair Value Disclosure	292,000,000			292,000,000		302,000,000
Other Real Estate Owned [Member] | Fair Value, Measurements, Nonrecurring [Member]
Asset Impairment Charges	6,000,000			8,000,000		10,000,000
Other Assets [Member] | Fair Value, Measurements, Nonrecurring [Member]
Asset Impairment Charges	7,000,000			13,000,000		61,000,000
Other Assets [Member] | Fair Value, Measurements, Nonrecurring [Member] | Land [Member]
Asset Impairment Charges	5,000,000		0	5,000,000	0
Other Assets [Member] | Fair Value, Measurements, Nonrecurring [Member] | Property Subject to Operating Lease [Member]
Asset Impairment Charges	2,000,000		0	8,000,000
Affordable Housing [Member] | Fair Value, Measurements, Nonrecurring [Member]
Asset Impairment Charges	$ 0	$ 36,000,000	$ 2,000,000	$ 36,000,000	$ 2,000,000	$ 3,000,000