Loans and Allowances for Credit Losses Part 4 (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	$ 172,353	$ 276,839	$ 172,353	$ 276,839	$ 245,856
Impaired loans, recorded investment, total	110,083	203,879	110,083	203,879	176,489
Impaired loans, recorded investment with no related allowance	101,033	173,676	101,033	173,676	154,595
Impaired loans, recorded investment with related allowance	9,050	30,203	9,050	30,203	21,894
Impaired loans, related allowance	3,667	6,700	3,667	6,700	5,776
Impaired loans, average recorded investment	118,203	190,108	143,290	203,196
Impaired loans, interest income recognized	0	0	0	0
Commercial Loan [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	43,821	110,831	43,821	110,831	93,932
Impaired loans, recorded investment, total	21,689	83,539	21,689	83,539	68,759
Impaired loans, recorded investment with no related allowance	20,352	79,923	20,352	79,923	66,439
Impaired loans, recorded investment with related allowance	1,337	3,616	1,337	3,616	2,320
Impaired loans, related allowance	204	1,799	204	1,799	1,536
Impaired loans, average recorded investment	28,060	68,353	45,226	60,933
Impaired loans, interest income recognized	0	0	0	0
Commercial Loan [Member] | Energy [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	3,273	3,900	3,273	3,900	336
Impaired loans, recorded investment, total	3,063	3,900	3,063	3,900	336
Impaired loans, recorded investment with no related allowance	3,063	3,900	3,063	3,900	336
Impaired loans, recorded investment with related allowance	0	0	0	0	0
Impaired loans, related allowance	0	0	0	0	0
Impaired loans, average recorded investment	3,075	2,123	1,700	2,183
Impaired loans, interest income recognized	0	0	0	0
Commercial Loan [Member] | Services [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	13,135	29,749	13,135	29,749	26,916
Impaired loans, recorded investment, total	10,099	18,181	10,099	18,181	16,968
Impaired loans, recorded investment with no related allowance	9,978	17,358	9,978	17,358	16,200
Impaired loans, recorded investment with related allowance	121	823	121	823	768
Impaired loans, related allowance	120	353	120	353	360
Impaired loans, average recorded investment	10,111	17,218	13,534	18,722
Impaired loans, interest income recognized	0	0	0	0
Commercial Loan [Member] | Wholesale/retail [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	8,039	32,226	8,039	32,226	24,432
Impaired loans, recorded investment, total	2,007	27,088	2,007	27,088	21,180
Impaired loans, recorded investment with no related allowance	1,937	25,345	1,937	25,345	19,702
Impaired loans, recorded investment with related allowance	70	1,743	70	1,743	1,478
Impaired loans, related allowance	18	1,104	18	1,104	1,102
Impaired loans, average recorded investment	3,091	26,113	11,594	17,787
Impaired loans, interest income recognized	0	0	0	0
Commercial Loan [Member] | Manufacturing [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	6,548	29,442	6,548	29,442	26,186
Impaired loans, recorded investment, total	2,283	27,691	2,283	27,691	23,051
Impaired loans, recorded investment with no related allowance	2,283	26,719	2,283	26,719	23,051
Impaired loans, recorded investment with related allowance	0	972	0	972	0
Impaired loans, related allowance	0	264	0	264	0
Impaired loans, average recorded investment	7,257	16,029	12,667	14,904
Impaired loans, interest income recognized	0	0	0	0
Commercial Loan [Member] | Healthcare [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	4,395	7,052	4,395	7,052	6,825
Impaired loans, recorded investment, total	3,305	5,715	3,305	5,715	5,486
Impaired loans, recorded investment with no related allowance	2,159	5,637	2,159	5,637	5,412
Impaired loans, recorded investment with related allowance	1,146	78	1,146	78	74
Impaired loans, related allowance	66	78	66	78	74
Impaired loans, average recorded investment	3,308	5,839	4,396	4,625
Impaired loans, interest income recognized	0	0	0	0
Commercial Loan [Member] | Integrated food services [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	0	0	0	0	0
Impaired loans, recorded investment, total	0	0	0	0	0
Impaired loans, recorded investment with no related allowance	0	0	0	0	0
Impaired loans, recorded investment with related allowance	0	0	0	0	0
Impaired loans, related allowance	0	0	0	0	0
Impaired loans, average recorded investment	0	0	0	7
Impaired loans, interest income recognized	0	0	0	0
Commercial Loan [Member] | Other commercial and industrial [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	8,431	8,462	8,431	8,462	9,237
Impaired loans, recorded investment, total	932	964	932	964	1,738
Impaired loans, recorded investment with no related allowance	932	964	932	964	1,738
Impaired loans, recorded investment with related allowance	0	0	0	0	0
Impaired loans, related allowance	0	0	0	0	0
Impaired loans, average recorded investment	1,218	1,031	1,335	2,705
Impaired loans, interest income recognized	0	0	0	0
Commercial Real Estate [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	112,954	153,935	112,954	153,935	141,500
Impaired loans, recorded investment, total	75,724	110,048	75,724	110,048	99,193
Impaired loans, recorded investment with no related allowance	68,441	87,866	68,441	87,866	82,080
Impaired loans, recorded investment with related allowance	7,283	22,182	7,283	22,182	17,113
Impaired loans, related allowance	3,117	4,199	3,117	4,199	3,942
Impaired loans, average recorded investment	77,967	110,206	87,460	130,209
Impaired loans, interest income recognized	0	0	0	0
Commercial Real Estate [Member] | Construction and land development [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	67,087	110,052	67,087	110,052	98,053
Impaired loans, recorded investment, total	38,143	72,207	38,143	72,207	61,874
Impaired loans, recorded investment with no related allowance	37,579	62,056	37,579	62,056	56,740
Impaired loans, recorded investment with related allowance	564	10,151	564	10,151	5,134
Impaired loans, related allowance	155	1,978	155	1,978	1,777
Impaired loans, average recorded investment	42,097	74,236	50,009	85,893
Impaired loans, interest income recognized	0	0	0	0
Commercial Real Estate [Member] | Retail [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	8,372	8,161	8,372	8,161	8,645
Impaired loans, recorded investment, total	6,692	6,492	6,692	6,492	6,863
Impaired loans, recorded investment with no related allowance	6,692	3,631	6,692	3,631	4,373
Impaired loans, recorded investment with related allowance	0	2,861	0	2,861	2,490
Impaired loans, related allowance	0	1,122	0	1,122	1,062
Impaired loans, average recorded investment	7,300	5,567	6,778	5,735
Impaired loans, interest income recognized	0	0	0	0
Commercial Real Estate [Member] | Office [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	13,736	14,199	13,736	14,199	14,588
Impaired loans, recorded investment, total	9,833	11,967	9,833	11,967	11,457
Impaired loans, recorded investment with no related allowance	9,608	11,405	9,608	11,405	9,567
Impaired loans, recorded investment with related allowance	225	562	225	562	1,890
Impaired loans, related allowance	21	76	21	76	291
Impaired loans, average recorded investment	10,211	11,720	10,645	15,811
Impaired loans, interest income recognized	0	0	0	0
Commercial Real Estate [Member] | Multifamily [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	3,259	5,326	3,259	5,326	3,512
Impaired loans, recorded investment, total	3,145	4,036	3,145	4,036	3,513
Impaired loans, recorded investment with no related allowance	3,145	4,036	3,145	4,036	3,513
Impaired loans, recorded investment with related allowance	0	0	0	0	0
Impaired loans, related allowance	0	0	0	0	0
Impaired loans, average recorded investment	3,182	4,377	3,329	5,381
Impaired loans, interest income recognized	0	0	0	0
Commercial Real Estate [Member] | Industrial [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	4,064	0	4,064	0	0
Impaired loans, recorded investment, total	4,064	0	4,064	0	0
Impaired loans, recorded investment with no related allowance	0	0	0	0	0
Impaired loans, recorded investment with related allowance	4,064	0	4,064	0	0
Impaired loans, related allowance	2,290	0	2,290	0	0
Impaired loans, average recorded investment	2,032	0	2,032	2,044
Impaired loans, interest income recognized	0	0	0	0
Commercial Real Estate [Member] | Other commercial real estate [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	16,436	16,197	16,436	16,197	16,702
Impaired loans, recorded investment, total	13,847	15,346	13,847	15,346	15,486
Impaired loans, recorded investment with no related allowance	11,417	6,738	11,417	6,738	7,887
Impaired loans, recorded investment with related allowance	2,430	8,608	2,430	8,608	7,599
Impaired loans, related allowance	651	1,023	651	1,023	812
Impaired loans, average recorded investment	13,145	14,306	14,667	15,345
Impaired loans, interest income recognized	0	0	0	0
Residential Mortgage [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	10,721	10,156	10,721	10,156	8,697
Impaired loans, recorded investment, total	9,855	8,903	9,855	8,903	7,441
Impaired loans, recorded investment with no related allowance	9,554	4,626	9,554	4,626	4,980
Impaired loans, recorded investment with related allowance	301	4,277	301	4,277	2,461
Impaired loans, related allowance	217	635	217	635	298
Impaired loans, average recorded investment	8,533	9,894	8,648	10,484
Impaired loans, interest income recognized	0	0	0	0
Residential Mortgage [Member] | Permanent mortgage [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	10,721	10,156	10,721	10,156	8,697
Impaired loans, recorded investment, total	9,855	8,903	9,855	8,903	7,441
Impaired loans, recorded investment with no related allowance	9,554	4,626	9,554	4,626	4,980
Impaired loans, recorded investment with related allowance	301	4,277	301	4,277	2,461
Impaired loans, related allowance	217	635	217	635	298
Impaired loans, average recorded investment	8,533	9,894	8,648	10,484
Impaired loans, interest income recognized	0	0	0	0
Residential Mortgage [Member] | Home equity [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	0	0	0	0	0
Impaired loans, recorded investment, total	0	0	0	0	0
Impaired loans, recorded investment with no related allowance	0	0	0	0	0
Impaired loans, recorded investment with related allowance	0	0	0	0	0
Impaired loans, related allowance	0	0	0	0	0
Impaired loans, average recorded investment	0	0	0	0
Impaired loans, interest income recognized	0	0	0	0
Consumer Loan [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	4,857	1,917	4,857	1,917	1,727
Impaired loans, recorded investment, total	2,815	1,389	2,815	1,389	1,096
Impaired loans, recorded investment with no related allowance	2,686	1,261	2,686	1,261	1,096
Impaired loans, recorded investment with related allowance	129	128	129	128	0
Impaired loans, related allowance	129	67	129	67	0
Impaired loans, average recorded investment	3,643	1,655	1,956	1,570
Impaired loans, interest income recognized	0	0	0	0
Consumer Loan [Member] | Indirect automobile [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	0	0	0	0	0
Impaired loans, recorded investment, total	0	0	0	0	0
Impaired loans, recorded investment with no related allowance	0	0	0	0	0
Impaired loans, recorded investment with related allowance	0	0	0	0	0
Impaired loans, related allowance	0	0	0	0	0
Impaired loans, average recorded investment	0	0	0	0
Impaired loans, interest income recognized	0	0	0	0
Consumer Loan [Member] | Other consumer [Member]
Impaired loans [Abstract]
Impaired loans, unpaid principal balance	4,857	1,917	4,857	1,917	1,727
Impaired loans, recorded investment, total	2,815	1,389	2,815	1,389	1,096
Impaired loans, recorded investment with no related allowance	2,686	1,261	2,686	1,261	1,096
Impaired loans, recorded investment with related allowance	129	128	129	128	0
Impaired loans, related allowance	129	67	129	67	0
Impaired loans, average recorded investment	3,643	1,655	1,956	1,570
Impaired loans, interest income recognized	$ 0	$ 0	$ 0	$ 0