Securitizations and Variable Interest Entities ("VIEs") (Schedule of Delinquencies, Net Credit Losses, and Components of Loan and Lease Sales) (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011
Securitizations And Variable Interest Entities [Line Items]
Principal Balance	$ 12,675,607		$ 9,702,694
Risk Assets	158,373	[1]	207,104	[1]
Net Credit Losses (Recoveries)	52,945		89,531
Loans And Leases Held In Portfolio [Member]
Securitizations And Variable Interest Entities [Line Items]
Principal Balance	12,503,737		9,503,538
Risk Assets	155,540	[1]	202,696	[1]
Net Credit Losses (Recoveries)	52,203		88,874
Home Equity Loans [Member]
Securitizations And Variable Interest Entities [Line Items]
Principal Balance	171,870		199,131
Risk Assets	2,833	[1]	4,399	[1]
Net Credit Losses (Recoveries)	745		653
Leases Serviced For Others [Member]
Securitizations And Variable Interest Entities [Line Items]
Principal Balance	0		25
Risk Assets	0	[1]	9	[1]
Net Credit Losses (Recoveries)	$ (3)		$ 4

[1] Includes nonaccrual loans and leases, foreclosed real estate, and loans and leases past due 90 days and still accruing.