Loans and Allowances for Credit Losses Part 5 (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	$ 97,985	$ 83,197
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	48,126	34,435
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	49,859	48,762
Troubled Debt Restructuring, Specific allowance	273	2,760
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	5,525	3,187
Accruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	38,515	32,891
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	8,755	13,298
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	29,760	19,593
Troubled Debt Restructuring, Specific allowance	0	0
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	0	233
Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	59,470	50,306
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	39,371	21,137
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	20,099	29,169
Troubled Debt Restructuring, Specific allowance	273	2,760
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	5,525	2,954
Commercial Loan [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	5,521	6,228
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	3,525	3,438
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	1,996	2,790
Troubled Debt Restructuring, Specific allowance	60	24
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	107	301
Commercial Loan [Member] | Energy [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	0	0
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Specific allowance	0	0
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	0	0
Commercial Loan [Member] | Services [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	2,492	3,529
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	2,099	1,907
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	393	1,622
Troubled Debt Restructuring, Specific allowance	45	0
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	0	301
Commercial Loan [Member] | Wholesale and retail [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	2,290	1,739
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	1,362	1,531
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	928	208
Troubled Debt Restructuring, Specific allowance	15	24
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	107	0
Commercial Loan [Member] | Manufacturing [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	0	0
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Specific allowance	0	0
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	0	0
Commercial Loan [Member] | Healthcare [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	64	0
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	64	0
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Specific allowance	0	0
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	0	0
Commercial Loan [Member] | Integrated food services [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	0	0
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Specific allowance	0	0
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	0	0
Commercial Loan [Member] | Other commercial and industrial [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	675	960
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	675	960
Troubled Debt Restructuring, Specific allowance	0	0
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	0	0
Commercial Real Estate [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	30,599	37,627
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	21,043	13,564
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	9,556	24,063
Troubled Debt Restructuring, Specific allowance	76	2,454
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	3,744	2,599
Commercial Real Estate [Member] | Construction and land development [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	14,898	25,890
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	9,989	10,310
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	4,909	15,580
Troubled Debt Restructuring, Specific allowance	76	1,577
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	1,143	1,104
Commercial Real Estate [Member] | Retail [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	6,785	1,070
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	5,735	0
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	1,050	1,070
Troubled Debt Restructuring, Specific allowance	0	0
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	150	882
Commercial Real Estate [Member] | Office [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	3,899	2,496
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	1,920	1,158
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	1,979	1,338
Troubled Debt Restructuring, Specific allowance	0	215
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	269	527
Commercial Real Estate [Member] | Multifamily [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	0	0
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Specific allowance	0	0
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	0	0
Commercial Real Estate [Member] | Industrial [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	0	0
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Specific allowance	0	0
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	0	0
Commercial Real Estate [Member] | Other commercial real estate [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	5,017	8,171
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	3,399	2,096
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	1,618	6,075
Troubled Debt Restructuring, Specific allowance	0	662
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	2,182	86
Residential Mortgage [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	38,515	32,891
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	8,755	13,298
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	29,760	19,593
Troubled Debt Restructuring, Specific allowance	0	0
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	0	233
Residential Mortgage [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	20,490	6,283
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	12,214	3,967
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	8,276	2,316
Troubled Debt Restructuring, Specific allowance	54	282
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	1,476	54
Residential Mortgage [Member] | Permanent mortgage [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	0	3,917
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	0	2,445
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	0	1,472
Troubled Debt Restructuring, Specific allowance	0	0
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	0	233
Residential Mortgage [Member] | Permanent mortgage [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	20,490	6,283
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	12,214	3,967
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	8,276	2,316
Troubled Debt Restructuring, Specific allowance	54	282
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	1,476	54
Residential Mortgage [Member] | Permanent mortgages guaranteed by U.S. government agencies [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	38,515	28,974
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	8,755	10,853
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	29,760	18,121
Troubled Debt Restructuring, Specific allowance	0	0
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	0	0
Residential Mortgage [Member] | Home equity [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	0	0
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Specific allowance	0	0
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	0	0
Consumer Loan [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	2,860	168
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	2,589	168
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	271	0
Troubled Debt Restructuring, Specific allowance	83	0
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	198	0
Consumer Loan [Member] | Indirect automobile [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	0	0
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	0	0
Troubled Debt Restructuring, Specific allowance	0	0
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	0	0
Consumer Loan [Member] | Other consumer [Member] | Nonaccrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled Debt Restructuring, Recorded Investment	2,860	168
Troubled Debt Restructuring, Performing in Accordance With Modified Terms	2,589	168
Troubled Debt Restructuring, Not Performing in Accordance With Modified Terms	271	0
Troubled Debt Restructuring, Specific allowance	83	0
Financing Receivables, Impaired, Troubled Debt Restructuring, Charge-offs	$ 198	$ 0