Loans, Allowance for Loan Losses, and Credit Quality (Details 7) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Summarized details of Loans
30-89 Days Past Due	$ 146,535	$ 151,381
90 Days or More Past Due	245,953	295,668
Total Past Due	392,488	447,049
Current	12,697,101	12,169,686
Ending balance all other loans collectively evaluated for impairment	12,521,635
Total loans	13,089,589	12,616,735
Consumer Loan [Member] | Accruing Loans [Member]
Summarized details of Loans
30-89 Days Past Due	31,242	32,232
90 Days or More Past Due	610	1,322
Total Past Due	31,852	33,554
Current	5,726,692	5,392,318
Ending balance all other loans collectively evaluated for impairment	5,758,544	5,425,872
Commercial Real Estate [Member] | Accruing Loans [Member]
Summarized details of Loans
30-89 Days Past Due	61,240	46,486
90 Days or More Past Due	7,297	2,096
Total Past Due	68,537	48,582
Current	3,161,654	3,116,704
Ending balance all other loans collectively evaluated for impairment	3,230,191	3,165,286
Real estate construction [Member] | Accruing Loans [Member]
Summarized details of Loans
30-89 Days Past Due	13,217	8,016
90 Days or More Past Due	0	0
Total Past Due	13,217	8,016
Current	447,805	450,124
Ending balance all other loans collectively evaluated for impairment	461,022	458,140
Total commercial [Member] | Accruing Loans [Member]
Summarized details of Loans
30-89 Days Past Due	82,117	87,647
90 Days or More Past Due	11,513	2,096
Total Past Due	93,630	89,743
Current	6,769,804	6,526,764
Ending balance all other loans collectively evaluated for impairment	6,863,434	6,616,507
Home Equity [Member] | Accruing Loans [Member]
Summarized details of Loans
30-89 Days Past Due	14,818	13,886
90 Days or More Past Due	0	796
Total Past Due	14,818	14,682
Current	2,532,434	2,456,663
Ending balance all other loans collectively evaluated for impairment	2,547,252	2,471,345
Installment [Member] | Accruing Loans [Member]
Summarized details of Loans
30-89 Days Past Due	3,851	9,624
90 Days or More Past Due	610	526
Total Past Due	4,461	10,150
Current	581,529	674,689
Ending balance all other loans collectively evaluated for impairment	585,990	684,839
Total retail [Member] | Accruing Loans [Member]
Summarized details of Loans
30-89 Days Past Due	18,669	23,510
90 Days or More Past Due	610	1,322
Total Past Due	19,279	24,832
Current	3,113,963	3,131,352
Ending balance all other loans collectively evaluated for impairment	3,133,242	3,156,184
Residential mortgage [Member] | Accruing Loans [Member]
Summarized details of Loans
30-89 Days Past Due	12,573	8,722
90 Days or More Past Due	0	0
Total Past Due	12,573	8,722
Current	2,612,729	2,260,966
Ending balance all other loans collectively evaluated for impairment	2,625,302	2,269,688
Accruing Loans [Member]
Summarized details of Loans
30-89 Days Past Due	113,359	119,879
90 Days or More Past Due	12,123	3,418
Total Past Due	125,482	123,297
Current	12,496,496	11,919,082
Ending balance all other loans collectively evaluated for impairment	12,621,978	12,042,379
Accruing Loans [Member] | Commercial and industrial financing receivable [Member]
Summarized details of Loans
30-89 Days Past Due	7,581	33,013
90 Days or More Past Due	4,216	0
Total Past Due	11,797	33,013
Current	3,119,321	2,916,894
Ending balance all other loans collectively evaluated for impairment	3,131,118	2,949,907
Accruing Loans [Member] | Finance Leases Financing Receivable [Member]
Summarized details of Loans
30-89 Days Past Due	79	132
90 Days or More Past Due	0	0
Total Past Due	79	132
Current	41,024	43,042
Ending balance all other loans collectively evaluated for impairment	41,103	43,174
Consumer Loan [Member] | Nonaccrual Loans [Member]
Summarized details of Loans
30-89 Days Past Due	9,456	15,067
90 Days or More Past Due	77,553	94,919
Total Past Due	87,009	109,986
Current	30,244	28,589
Ending balance all other loans collectively evaluated for impairment	117,253	138,575
Commercial Real Estate [Member] | Nonaccrual Loans [Member]
Summarized details of Loans
30-89 Days Past Due	15,015	12,429
90 Days or More Past Due	82,967	82,675
Total Past Due	97,982	95,104
Current	95,513	128,823
Ending balance all other loans collectively evaluated for impairment	193,495	223,927
Real estate construction [Member] | Nonaccrual Loans [Member]
Summarized details of Loans
30-89 Days Past Due	894	297
90 Days or More Past Due	44,763	56,443
Total Past Due	45,657	56,740
Current	27,125	38,189
Ending balance all other loans collectively evaluated for impairment	72,782	94,929
Total commercial [Member] | Nonaccrual Loans [Member]
Summarized details of Loans
30-89 Days Past Due	23,720	16,435
90 Days or More Past Due	156,277	197,331
Total Past Due	179,997	213,766
Current	170,361	222,015
Ending balance all other loans collectively evaluated for impairment	350,358	435,781
Home Equity [Member] | Nonaccrual Loans [Member]
Summarized details of Loans
30-89 Days Past Due	4,281	5,727
90 Days or More Past Due	31,480	37,169
Total Past Due	35,761	42,896
Current	11,016	8,816
Ending balance all other loans collectively evaluated for impairment	46,777	51,712
Installment [Member] | Nonaccrual Loans [Member]
Summarized details of Loans
30-89 Days Past Due	533	1,091
90 Days or More Past Due	950	7,141
Total Past Due	1,483	8,232
Current	2,241	2,312
Ending balance all other loans collectively evaluated for impairment	3,724	10,544
Total retail [Member] | Nonaccrual Loans [Member]
Summarized details of Loans
30-89 Days Past Due	4,814	6,818
90 Days or More Past Due	32,430	44,310
Total Past Due	37,244	51,128
Current	13,257	11,128
Ending balance all other loans collectively evaluated for impairment	50,501	62,256
Residential mortgage [Member] | Nonaccrual Loans [Member]
Summarized details of Loans
30-89 Days Past Due	4,642	8,249
90 Days or More Past Due	45,123	50,609
Total Past Due	49,765	58,858
Current	16,987	17,461
Ending balance all other loans collectively evaluated for impairment	66,752	76,319
Nonaccrual Loans [Member]
Summarized details of Loans
30-89 Days Past Due	33,176	31,502
90 Days or More Past Due	233,830	292,250
Total Past Due	267,006	323,752
Current	200,605	250,604
Ending balance all other loans collectively evaluated for impairment	467,611	574,356
Nonaccrual Loans [Member] | Commercial and industrial financing receivable [Member]
Summarized details of Loans
30-89 Days Past Due	7,500	3,426
90 Days or More Past Due	28,436	57,215
Total Past Due	35,936	60,641
Current	35,247	39,204
Ending balance all other loans collectively evaluated for impairment	71,183	99,845
Nonaccrual Loans [Member] | Finance Leases Financing Receivable [Member]
Summarized details of Loans
30-89 Days Past Due	311	283
90 Days or More Past Due	111	998
Total Past Due	422	1,281
Current	12,476	15,799
Ending balance all other loans collectively evaluated for impairment	12,898	17,080
Commercial and industrial financing receivable [Member]
Summarized details of Loans
30-89 Days Past Due	15,081	36,439
90 Days or More Past Due	32,652	57,215
Total Past Due	47,733	93,654
Current	3,154,568	2,956,098
Ending balance all other loans collectively evaluated for impairment	3,202,301	3,049,752
Commercial Real Estate [Member]
Summarized details of Loans
30-89 Days Past Due	76,255	58,915
90 Days or More Past Due	90,264	84,771
Total Past Due	166,519	143,686
Current	3,257,167	3,245,527
Ending balance all other loans collectively evaluated for impairment	3,423,686	3,389,213
Real estate construction [Member]
Summarized details of Loans
30-89 Days Past Due	14,111	8,313
90 Days or More Past Due	44,763	56,443
Total Past Due	58,874	64,756
Current	474,930	488,313
Ending balance all other loans collectively evaluated for impairment	533,804	553,069
Finance Leases Financing Receivable [Member]
Summarized details of Loans
30-89 Days Past Due	390	415
90 Days or More Past Due	111	998
Total Past Due	501	1,413
Current	53,500	58,841
Ending balance all other loans collectively evaluated for impairment	54,001	60,254
Total commercial [Member]
Summarized details of Loans
30-89 Days Past Due	105,837	104,082
90 Days or More Past Due	167,790	199,427
Total Past Due	273,627	303,509
Current	6,940,165	6,748,779
Ending balance all other loans collectively evaluated for impairment	7,213,792	7,052,288
Home Equity [Member]
Summarized details of Loans
30-89 Days Past Due	19,099	19,613
90 Days or More Past Due	31,480	37,965
Total Past Due	50,579	57,578
Current	2,543,450	2,465,479
Ending balance all other loans collectively evaluated for impairment	2,594,029	2,523,057
Installment [Member]
Summarized details of Loans
30-89 Days Past Due	4,384	10,715
90 Days or More Past Due	1,560	7,667
Total Past Due	5,944	18,382
Current	583,770	677,001
Ending balance all other loans collectively evaluated for impairment	589,714	695,383
Total retail [Member]
Summarized details of Loans
30-89 Days Past Due	23,483	30,328
90 Days or More Past Due	33,040	45,632
Total Past Due	56,523	75,960
Current	3,127,220	3,142,480
Ending balance all other loans collectively evaluated for impairment	3,183,743	3,218,440
Residential mortgage [Member]
Summarized details of Loans
30-89 Days Past Due	17,215	16,971
90 Days or More Past Due	45,123	50,609
Total Past Due	62,338	67,580
Current	2,629,716	2,278,427
Ending balance all other loans collectively evaluated for impairment	2,692,054	2,346,007
Consumer Loan [Member]
Summarized details of Loans
30-89 Days Past Due	40,698	47,299
90 Days or More Past Due	78,163	96,241
Total Past Due	118,861	143,540
Current	5,756,936	5,420,907
Ending balance all other loans collectively evaluated for impairment	$ 5,875,797	$ 5,564,447