Fair Value Measurement (Details 4) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011
Financial assets:
Cash and due from banks	$ 64,024	$ 73,652
Indemnification asset	2,485	4,405
Financial liabilities:
Other borrowings	9,264	72,541	82,919
Junior subordinated debt	41,238	41,238	41,238
Carrying Amount [Member] | Level 1 inputs [Member]
Financial assets:
Cash and due from banks	64,024	73,652
Cash at Federal Reserve and other banks	558,470	563,623
Carrying Amount [Member] | Level 2 inputs [Member]
Financial assets:
Restricted equity securities	9,647	10,610
Loans held for sale	14,937	10,219
Financial liabilities:
Deposits	2,201,639	2,190,536
Other borrowings	9,264	72,541
Junior subordinated debt	41,238	41,238
Carrying Amount [Member] | Level 3 inputs [Member]
Financial assets:
Loans, net	1,531,501	1,505,118
Indemnification asset	2,485	4,405
Fair Value [Member] | Level 1 inputs [Member]
Financial assets:
Cash and due from banks	64,020	73,652
Cash at Federal Reserve and other banks	558,470	563,623
Fair Value [Member] | Level 2 inputs [Member]
Financial assets:
Restricted equity securities	9,647	10,610
Loans held for sale	14,937	10,219
Financial liabilities:
Deposits	2,204,077	2,193,170
Other borrowings	9,264	74,027
Junior subordinated debt	28,660	25,980
Fair Value [Member] | Level 3 inputs [Member]
Financial assets:
Loans, net	1,622,132	1,579,084
Indemnification asset	2,485	4,405
Off-balance sheet:
Commitments	5,277	5,290
Standby letters of credit	27	53
Overdraft privilege commitments	679	616
Contract Amount [Member] | Level 3 inputs [Member]
Off-balance sheet:
Commitments	527,741	529,046
Standby letters of credit	2,663	5,324
Overdraft privilege commitments	$ 67,947	$ 61,623