Fair Value of Financial Instruments (Summary of Carrying Amounts and Estimated Fair Values of Selected Financial Instruments) (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Cash and due from banks	$ 89,926	$ 55,492
Interest-earning deposits with banks	179,573	458,638
Securities available for sale	989,768	763,866
FHLB stock	18,791	17,908
Loans	2,540,727	2,371,822
FDIC loss-sharing asset	206,238	205,991
Interest rate contracts	10,476
Deposits	3,475,167	3,327,269
FHLB Advances	120,681	119,405
Repurchase agreements	25,000	25,000
Other borrowings	0	642
Long-term subordinated debt	25,768	25,735
Interest rate contracts	10,476
Carrying Amount [Member]
Cash and due from banks	89,926	55,492
Interest-earning deposits with banks	179,573	458,638
Securities available for sale	989,768	763,866
FHLB stock	18,791	17,908
Loans held for sale	655	754
Loans	2,540,727	2,371,822
FDIC loss-sharing asset	206,238	205,991
Interest rate contracts	10,476	10,167
Deposits	3,475,167	3,327,269
FHLB Advances	120,681	119,405
Repurchase agreements	25,000	25,000
Other borrowings	0	642
Long-term subordinated debt	25,768	25,735
Interest rate contracts	10,476	10,167
Fair Value [Member]
Cash and due from banks	89,926	55,492
Interest-earning deposits with banks	179,573	458,638
Securities available for sale	989,768	763,866
FHLB stock	18,791	17,908
Loans held for sale	655	754
Loans	2,806,335	2,525,113
FDIC loss-sharing asset	206,238	205,991
Interest rate contracts	10,476	10,167
Deposits	3,447,132	3,330,616
FHLB Advances	123,277	122,722
Repurchase agreements	27,099	27,251
Other borrowings	0	642
Long-term subordinated debt	22,655	20,156
Interest rate contracts	$ 10,476	$ 10,167