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	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Securitizations And Variable Interest Entities [Line Items]
Recorded Investment	$ 12,999,703		$ 12,521,669
Risk Assets	132,304	[1]	179,703	[1]
Net Credit Losses (Recoveries)	20,056		12,610
Loans And Leases Held In Portfolio [Member]
Securitizations And Variable Interest Entities [Line Items]
Recorded Investment	12,840,305		12,337,688
Risk Assets	130,104	[1]	176,445	[1]
Net Credit Losses (Recoveries)	19,643		12,370
Home Equity Loans Held By VIEs [Member]
Securitizations And Variable Interest Entities [Line Items]
Recorded Investment	159,398		183,981
Risk Assets	2,200	[1]	3,258	[1]
Net Credit Losses (Recoveries)	413		240
Leases Serviced For Others [Member]
Securitizations And Variable Interest Entities [Line Items]
Recorded Investment	0		0
Risk Assets	0	[1]	0	[1]
Net Credit Losses (Recoveries)	$ 0		$ 0

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