Loans (Details 4) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Impaired loans
Impaired Financing Receivable, With No Related Allowance, Unpaid Principal Balance	$ 61,065	$ 29,819
Impaired Financing Receivable, With No Related Allowance, Recorded Investment	48,622	29,862
Impaired Financing Receivable, With No Related Allowance For Loan Losses Allocated	0	0
Impaired Financing Receivable, With Related Allowance, Unpaid Principal Balance	2,581	18,130
Impaired Financing Receivable, With Related Allowance, Recorded Investment	1,978	18,139
Impaired Financing Receivable, Allowance For Loan Losses Allocated, Related Allowance	719	7,200
Residential Owner Occupied [Member]
Impaired loans
Impaired Financing Receivable, With No Related Allowance, Unpaid Principal Balance	949	981
Impaired Financing Receivable, With No Related Allowance, Recorded Investment	918	984
Impaired Financing Receivable, With No Related Allowance For Loan Losses Allocated	0	0
Impaired Financing Receivable, With Related Allowance, Unpaid Principal Balance	969	1,020
Impaired Financing Receivable, With Related Allowance, Recorded Investment	902	1,020
Impaired Financing Receivable, Allowance For Loan Losses Allocated, Related Allowance	191	373
Residential Non Owner Occupied [Member]
Impaired loans
Impaired Financing Receivable, With No Related Allowance, Unpaid Principal Balance	7,709	1,871
Impaired Financing Receivable, With No Related Allowance, Recorded Investment	6,934	1,877
Impaired Financing Receivable, With No Related Allowance For Loan Losses Allocated	0	0
Impaired Financing Receivable, With Related Allowance, Unpaid Principal Balance	0	726
Impaired Financing Receivable, With Related Allowance, Recorded Investment	0	726
Impaired Financing Receivable, Allowance For Loan Losses Allocated, Related Allowance	0	281
Residential Real Estate [Member]
Impaired loans
Impaired Financing Receivable, With No Related Allowance, Unpaid Principal Balance	8,658	2,852
Impaired Financing Receivable, With No Related Allowance, Recorded Investment	7,852	2,861
Impaired Financing Receivable, With No Related Allowance For Loan Losses Allocated	0	0
Impaired Financing Receivable, With Related Allowance, Unpaid Principal Balance	969	1,746
Impaired Financing Receivable, With Related Allowance, Recorded Investment	902	1,746
Impaired Financing Receivable, Allowance For Loan Losses Allocated, Related Allowance	191	654
Construction Loans [Member]
Impaired loans
Impaired Financing Receivable, With No Related Allowance, Unpaid Principal Balance	0	0
Impaired Financing Receivable, With No Related Allowance, Recorded Investment	0	0
Impaired Financing Receivable, With No Related Allowance For Loan Losses Allocated	0	0
Impaired Financing Receivable, With Related Allowance, Unpaid Principal Balance	0	0
Impaired Financing Receivable, With Related Allowance, Recorded Investment	0	0
Impaired Financing Receivable, Allowance For Loan Losses Allocated, Related Allowance	0	0
Multi Family [Member]
Impaired loans
Impaired Financing Receivable, With No Related Allowance, Unpaid Principal Balance	1,346	1,138
Impaired Financing Receivable, With No Related Allowance, Recorded Investment	1,181	1,137
Impaired Financing Receivable, With No Related Allowance For Loan Losses Allocated	0	0
Impaired Financing Receivable, With Related Allowance, Unpaid Principal Balance	0	298
Impaired Financing Receivable, With Related Allowance, Recorded Investment	0	298
Impaired Financing Receivable, Allowance For Loan Losses Allocated, Related Allowance	0	195
Commercial Real Estate Owner Occupied [Member]
Impaired loans
Impaired Financing Receivable, With No Related Allowance, Unpaid Principal Balance	14,643	5,868
Impaired Financing Receivable, With No Related Allowance, Recorded Investment	11,545	5,879
Impaired Financing Receivable, With No Related Allowance For Loan Losses Allocated	0	0
Impaired Financing Receivable, With Related Allowance, Unpaid Principal Balance	1,007	2,284
Impaired Financing Receivable, With Related Allowance, Recorded Investment	834	2,284
Impaired Financing Receivable, Allowance For Loan Losses Allocated, Related Allowance	376	589
Commercial Real Estate Non Owner Occupied [Member]
Impaired loans
Impaired Financing Receivable, With No Related Allowance, Unpaid Principal Balance	17,272	8,408
Impaired Financing Receivable, With No Related Allowance, Recorded Investment	15,235	8,421
Impaired Financing Receivable, With No Related Allowance For Loan Losses Allocated	0	0
Impaired Financing Receivable, With Related Allowance, Unpaid Principal Balance	585	8,589
Impaired Financing Receivable, With Related Allowance, Recorded Investment	222	8,596
Impaired Financing Receivable, Allowance For Loan Losses Allocated, Related Allowance	144	3,235
Agriculture Land [Member]
Impaired loans
Impaired Financing Receivable, With No Related Allowance, Unpaid Principal Balance	1,159	1,072
Impaired Financing Receivable, With No Related Allowance, Recorded Investment	961	1,073
Impaired Financing Receivable, With No Related Allowance For Loan Losses Allocated	0	0
Impaired Financing Receivable, With Related Allowance, Unpaid Principal Balance	0	300
Impaired Financing Receivable, With Related Allowance, Recorded Investment	0	300
Impaired Financing Receivable, Allowance For Loan Losses Allocated, Related Allowance	0	163
Commercial Real Estate Other Receivables [Member]
Impaired loans
Impaired Financing Receivable, With No Related Allowance, Unpaid Principal Balance	9,694	5,607
Impaired Financing Receivable, With No Related Allowance, Recorded Investment	5,359	5,605
Impaired Financing Receivable, With No Related Allowance For Loan Losses Allocated	0	0
Impaired Financing Receivable, With Related Allowance, Unpaid Principal Balance	0	2,676
Impaired Financing Receivable, With Related Allowance, Recorded Investment	0	2,676
Impaired Financing Receivable, Allowance For Loan Losses Allocated, Related Allowance	0	1,413
Commercial Working Capital [Member]
Impaired loans
Impaired Financing Receivable, With No Related Allowance, Unpaid Principal Balance	2,378	1,391
Impaired Financing Receivable, With No Related Allowance, Recorded Investment	2,292	1,393
Impaired Financing Receivable, With No Related Allowance For Loan Losses Allocated	0	0
Impaired Financing Receivable, With Related Allowance, Unpaid Principal Balance	0	358
Impaired Financing Receivable, With Related Allowance, Recorded Investment	0	358
Impaired Financing Receivable, Allowance For Loan Losses Allocated, Related Allowance	0	192
Commercial Loans Other [Member]
Impaired loans
Impaired Financing Receivable, With No Related Allowance, Unpaid Principal Balance	5,899	3,444
Impaired Financing Receivable, With No Related Allowance, Recorded Investment	4,181	3,453
Impaired Financing Receivable, With No Related Allowance For Loan Losses Allocated	0	0
Impaired Financing Receivable, With Related Allowance, Unpaid Principal Balance	0	1,879
Impaired Financing Receivable, With Related Allowance, Recorded Investment	0	1,881
Impaired Financing Receivable, Allowance For Loan Losses Allocated, Related Allowance	0	777
Commercial Loan [Member]
Impaired loans
Impaired Financing Receivable, With No Related Allowance, Unpaid Principal Balance	8,277	4,835
Impaired Financing Receivable, With No Related Allowance, Recorded Investment	6,473	4,846
Impaired Financing Receivable, With No Related Allowance For Loan Losses Allocated	0	0
Impaired Financing Receivable, With Related Allowance, Unpaid Principal Balance	0	2,237
Impaired Financing Receivable, With Related Allowance, Recorded Investment	0	2,239
Impaired Financing Receivable, Allowance For Loan Losses Allocated, Related Allowance	0	969
Commercial Real Estate [Member]
Impaired loans
Impaired Financing Receivable, With No Related Allowance, Unpaid Principal Balance	42,768	20,955
Impaired Financing Receivable, With No Related Allowance, Recorded Investment	33,100	20,978
Impaired Financing Receivable, With No Related Allowance For Loan Losses Allocated	0	0
Impaired Financing Receivable, With Related Allowance, Unpaid Principal Balance	1,592	13,849
Impaired Financing Receivable, With Related Allowance, Recorded Investment	1,056	13,856
Impaired Financing Receivable, Allowance For Loan Losses Allocated, Related Allowance	520	5,400
Consumer Loan [Member]
Impaired loans
Impaired Financing Receivable, With No Related Allowance, Unpaid Principal Balance	0	0
Impaired Financing Receivable, With No Related Allowance, Recorded Investment	0	0
Impaired Financing Receivable, With No Related Allowance For Loan Losses Allocated	0	0
Impaired Financing Receivable, With Related Allowance, Unpaid Principal Balance	0	0
Impaired Financing Receivable, With Related Allowance, Recorded Investment	0	0
Impaired Financing Receivable, Allowance For Loan Losses Allocated, Related Allowance	0	0
Home Equity [Member]
Impaired loans
Impaired Financing Receivable, With No Related Allowance, Unpaid Principal Balance	16	39
Impaired Financing Receivable, With No Related Allowance, Recorded Investment	16	40
Impaired Financing Receivable, With No Related Allowance For Loan Losses Allocated	0	0
Impaired Financing Receivable, With Related Allowance, Unpaid Principal Balance	20	0
Impaired Financing Receivable, With Related Allowance, Recorded Investment	20	0
Impaired Financing Receivable, Allowance For Loan Losses Allocated, Related Allowance	$ 8	$ 0