Loans And Leases (Recorded Investment In Loans And Leases) (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Schedule Of Recorded Investment In Loans And Leases [Line Items]
Ending balance	$ 11,727,652	$ 11,225,404
Accrued interest	36,366	33,540
Total recorded investment	11,764,018	11,258,944
Total recorded investment: individually evaluated for impairment	477,213	495,276
Total recorded investment: collectively evaluated for impairment	11,286,805	10,763,668
Residential Mortgage [Member]
Schedule Of Recorded Investment In Loans And Leases [Line Items]
Ending balance	3,292,948	3,219,890
Accrued interest	10,971	10,992
Total recorded investment	3,303,919	3,230,882
Total recorded investment: individually evaluated for impairment	148,582	135,311
Total recorded investment: collectively evaluated for impairment	3,155,337	3,095,571
Consumer Loan [Member]
Schedule Of Recorded Investment In Loans And Leases [Line Items]
Ending balance	2,668,004	2,760,030
Accrued interest	8,523	8,777
Total recorded investment	2,676,527	2,768,807
Total recorded investment: individually evaluated for impairment	62,268	36,629
Total recorded investment: collectively evaluated for impairment	2,614,259	2,732,178
Commercial Loan [Member]
Schedule Of Recorded Investment In Loans And Leases [Line Items]
Ending balance	2,737,059	2,385,791
Accrued interest	9,375	6,585
Total recorded investment	2,746,434	2,392,376
Total recorded investment: individually evaluated for impairment	80,933	107,218
Total recorded investment: collectively evaluated for impairment	2,665,501	2,285,158
Commercial Real Estate [Member]
Schedule Of Recorded Investment In Loans And Leases [Line Items]
Ending balance	2,627,893	2,384,889
Accrued interest	7,497	7,186
Total recorded investment	2,635,390	2,392,075
Total recorded investment: individually evaluated for impairment	184,284	212,850
Total recorded investment: collectively evaluated for impairment	2,451,106	2,179,225
Financing [Member]
Schedule Of Recorded Investment In Loans And Leases [Line Items]
Ending balance	401,748	474,804
Accrued interest	0	0
Total recorded investment	401,748	474,804
Total recorded investment: individually evaluated for impairment	1,146	3,268
Total recorded investment: collectively evaluated for impairment	$ 400,602	$ 471,536