Fair Value Measurement and Election - Additional Information (Detail) (USD $)	3 Months Ended					3 Months Ended			3 Months Ended			3 Months Ended		12 Months Ended	3 Months Ended							12 Months Ended	3 Months Ended	12 Months Ended										3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Mar. 31, 2014 Total Return Swap Fair Value, Inputs, Level 2 [Member]	Dec. 31, 2013 Total Return Swap Fair Value, Inputs, Level 2 [Member]	Mar. 31, 2014 Interest Rate Lock Commitments	Mar. 31, 2013 Interest Rate Lock Commitments	Dec. 31, 2013 Asset-backed Securities [Member] Student Loans [Member]	Mar. 31, 2014 Trading Account Assets [Member] Commercial and Corporate Leveraged Loans [Member] Fair Value, Inputs, Level 2 [Member]	Mar. 31, 2013 Trading Account Assets [Member] Commercial and Corporate Leveraged Loans [Member] Fair Value, Inputs, Level 2 [Member]	Dec. 31, 2013 Trading Account Assets [Member] Commercial and Corporate Leveraged Loans [Member] Fair Value, Inputs, Level 2 [Member]	Mar. 31, 2014 Residential Mortgage, Loans Held For Sale [Member] Fair Value, Inputs, Level 2 [Member]	Mar. 31, 2013 Residential Mortgage, Loans Held For Sale [Member] Fair Value, Inputs, Level 2 [Member]	Dec. 31, 2013 Residential Mortgage, Loans Held For Sale [Member] Nonperforming Financing Receivable [Member]	Mar. 31, 2014 Collateralized Loan Obligations [Member] Fair Value, Inputs, Level 2 [Member]	Mar. 31, 2013 Collateralized Loan Obligations [Member] Fair Value, Inputs, Level 2 [Member]	Mar. 31, 2014 Brokered Deposits [Member] Fair Value, Inputs, Level 2 [Member]	Mar. 31, 2013 Brokered Deposits [Member] Fair Value, Inputs, Level 2 [Member]	Mar. 31, 2014 Long-term Debt [Member] Fair Value, Inputs, Level 2 [Member]	Mar. 31, 2013 Long-term Debt [Member] Fair Value, Inputs, Level 2 [Member]	Mar. 31, 2014 Loans Held For Sale [Member] Nonperforming Financing Receivable [Member]	Dec. 31, 2013 Loans Held For Sale [Member] Nonperforming Financing Receivable [Member]	Mar. 31, 2013 Loans Held For Sale [Member] Residential Portfolio Segment [Member]	Dec. 31, 2013 Loans Held For Sale [Member] Nonperforming Residential Mortgages Transferred To Held For Sale During Period [Member]	Mar. 31, 2014 Commercial and Corporate Loans [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2013 Commercial and Corporate Loans [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Mar. 31, 2014 Commercial and Corporate Loans [Member] Variable Interest Entity, Not Primary Beneficiary [Member] Preference Shares [Member]	Dec. 31, 2013 Commercial and Corporate Loans [Member] Variable Interest Entity, Not Primary Beneficiary [Member] Preference Shares [Member]	Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member]	Mar. 31, 2014 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 3 [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 3 [Member]	Mar. 31, 2014 Collateralized Debt Obligations [Member] Fair Value, Inputs, Level 2 [Member]	Mar. 31, 2014 Other Real Estate Owned [Member] Fair Value, Measurements, Nonrecurring [Member]	Dec. 31, 2013 Other Real Estate Owned [Member] Fair Value, Measurements, Nonrecurring [Member]	Mar. 31, 2014 Other Assets [Member] Fair Value, Measurements, Nonrecurring [Member]	Dec. 31, 2013 Other Assets [Member] Fair Value, Measurements, Nonrecurring [Member]	Mar. 31, 2014 Other Assets [Member] Fair Value, Measurements, Nonrecurring [Member] Repossessed Personal Property [Member]	Dec. 31, 2013 Other Assets [Member] Fair Value, Measurements, Nonrecurring [Member] Repossessed Personal Property [Member]	Mar. 31, 2014 Other Assets [Member] Fair Value, Measurements, Nonrecurring [Member] Property Subject to Operating Lease [Member]	Dec. 31, 2013 Other Assets [Member] Fair Value, Measurements, Nonrecurring [Member] Private Equity Partnership Investments [Member]	Mar. 31, 2014 Affordable Housing [Member] Fair Value, Measurements, Nonrecurring [Member]	Dec. 31, 2013 Affordable Housing [Member] Fair Value, Measurements, Nonrecurring [Member]
Assets	$ 179,542,000,000		$ 175,335,000,000																						$ 1,700,000,000	$ 1,600,000,000	$ 3,000,000	$ 3,000,000
Transfer of Loans Held-for-sale to Portfolio Loans	17,000,000	12,000,000
Government guaranteed percent								97.00%
Loans Receivable, Fair Value Disclosure	299,000,000		302,000,000	1,400,000,000	1,500,000,000				406,000,000		313,000,000																		0	0	299,000,000	302,000,000
Fair Value, Option, Credit Risk, Gains (Losses) on Assets									2,000,000	2,000,000		1,000,000	0		0	2,000,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3						55,000,000	135,000,000
Fair Value, Option, Credit Risk, Gains (Losses) on Liabilities																	(1,000,000)	(1,000,000)	(17,000,000)	(21,000,000)
Debt Instrument, Fair Value Disclosure																																	238,000,000
Transfer Of Portfolio Loans And Leases To Held For Sale Net Of Impairment																					0	7,000,000
Allowance for Loan and Lease Losses, Write-offs	(151,000,000)	(273,000,000)																						(1,000,000)
Loans held for investment sold	85,000,000	503,000,000												17,000,000
Gain (Loss) on Sales of Loans, Net	9,000,000	4,000,000																					3,000,000
Asset Impairment Charges																																		4,000,000	10,000,000	7,000,000	61,000,000	5,000,000	4,000,000	2,000,000	0	36,000,000	3,000,000
Unfunded loan commitments and letters of credit	50,900,000,000		48,900,000,000
Allowance for unfunded loan commitments and letters of credit	$ 49,000,000		$ 53,000,000