Fair Value Option and Fair Value Measurements (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2012 Level 1	Dec. 31, 2011 Level 1	Jun. 30, 2012 Level 2	Dec. 31, 2011 Level 2	Jun. 30, 2012 Level 3	Dec. 31, 2011 Level 3	Jun. 30, 2012 Recurring basis Level 1	Dec. 31, 2011 Recurring basis Level 1	Jun. 30, 2012 Recurring basis Level 1 U.S. Treasury	Dec. 31, 2011 Recurring basis Level 1 U.S. Treasury	Jun. 30, 2012 Recurring basis Level 1 Asset-backed securities	Mar. 31, 2012 Recurring basis Level 1 Asset-backed securities	Jun. 30, 2012 Recurring basis Level 2	Dec. 31, 2011 Recurring basis Level 2	Jun. 30, 2012 Recurring basis Level 2 Interest rate swap agreements net of swap credit valuation	Dec. 31, 2011 Recurring basis Level 2 Interest rate swap agreements net of swap credit valuation	Jun. 30, 2012 Recurring basis Level 2 Forward MBS	Dec. 31, 2011 Recurring basis Level 2 Forward MBS	Jun. 30, 2012 Recurring basis Level 2 Interest rate lock commitments to borrowers	Dec. 31, 2011 Recurring basis Level 2 Interest rate lock commitments to borrowers	Jun. 30, 2012 Recurring basis Level 2 U.S. government agencies	Dec. 31, 2011 Recurring basis Level 2 U.S. government agencies	Jun. 30, 2012 Recurring basis Level 2 U.S. government agency mortgage-backed	Dec. 31, 2011 Recurring basis Level 2 U.S. government agency mortgage-backed	Jun. 30, 2012 Recurring basis Level 2 States and political subdivisions	Dec. 31, 2011 Recurring basis Level 2 States and political subdivisions	Jun. 30, 2012 Recurring basis Level 2 Corporate bonds	Dec. 31, 2011 Recurring basis Level 2 Corporate bonds	Jun. 30, 2012 Recurring basis Level 2 Collateralized mortgage obligations	Dec. 31, 2011 Recurring basis Level 2 Collateralized mortgage obligations	Jun. 30, 2012 Recurring basis Level 2 Asset-backed securities	Dec. 31, 2011 Recurring basis Level 2 Asset-backed securities	Jun. 30, 2012 Recurring basis Level 3	Dec. 31, 2011 Recurring basis Level 3	Jun. 30, 2012 Recurring basis Level 3 Interest rate swap agreements net of swap credit valuation	Dec. 31, 2011 Recurring basis Level 3 Interest rate swap agreements net of swap credit valuation	Jun. 30, 2012 Recurring basis Level 3 States and political subdivisions	Dec. 31, 2011 Recurring basis Level 3 States and political subdivisions	Jun. 30, 2012 Recurring basis Level 3 Collateralized debt obligations	Dec. 31, 2011 Recurring basis Level 3 Collateralized debt obligations	Jun. 30, 2012 Recurring basis Total	Dec. 31, 2011 Recurring basis Total	Jun. 30, 2012 Recurring basis Total Interest rate swap agreements net of swap credit valuation	Dec. 31, 2011 Recurring basis Total Interest rate swap agreements net of swap credit valuation	Jun. 30, 2012 Recurring basis Total Forward MBS	Dec. 31, 2011 Recurring basis Total Forward MBS	Jun. 30, 2012 Recurring basis Total Interest rate lock commitments to borrowers	Dec. 31, 2011 Recurring basis Total Interest rate lock commitments to borrowers	Jun. 30, 2012 Recurring basis Total U.S. Treasury	Dec. 31, 2011 Recurring basis Total U.S. Treasury	Jun. 30, 2012 Recurring basis Total U.S. government agencies	Dec. 31, 2011 Recurring basis Total U.S. government agencies	Jun. 30, 2012 Recurring basis Total U.S. government agency mortgage-backed	Dec. 31, 2011 Recurring basis Total U.S. government agency mortgage-backed	Jun. 30, 2012 Recurring basis Total States and political subdivisions	Dec. 31, 2011 Recurring basis Total States and political subdivisions	Jun. 30, 2012 Recurring basis Total Corporate bonds	Dec. 31, 2011 Recurring basis Total Corporate bonds	Jun. 30, 2012 Recurring basis Total Collateralized mortgage obligations	Dec. 31, 2011 Recurring basis Total Collateralized mortgage obligations	Jun. 30, 2012 Recurring basis Total Asset-backed securities	Dec. 31, 2011 Recurring basis Total Asset-backed securities	Jun. 30, 2012 Recurring basis Total Collateralized debt obligations	Dec. 31, 2011 Recurring basis Total Collateralized debt obligations
Assets:
Investment securities available-for-sale					$ 53,267	$ 1,524	$ 336,327	$ 295,928	$ 9,301	$ 10,112			$ 1,515	$ 1,524	$ 51,752	$ 3,300									$ 44,623	$ 43,398	$ 95,208	$ 154,007	$ 13,920	$ 13,671	$ 35,267	$ 31,389	$ 62,387	$ 25,122	$ 84,922	$ 28,341					$ 138	$ 138	$ 9,163	$ 9,974									$ 1,515	$ 1,524	$ 44,623	$ 43,398	$ 95,208	$ 154,007	$ 14,058	$ 13,809	$ 35,267	$ 31,389	$ 62,387	$ 25,122	$ 136,674	$ 28,341	$ 9,163	$ 9,974
Loans held-for-sale							6,445	12,806									6,445	12,806																											6,445	12,806
Mortgage servicing rights	3,531	3,487	4,018	3,897																																	3,531	3,487							3,531	3,487
Other assets																			2,606	3,152	910	107																	(69)	(80)							2,537	3,072	910	107
Assets at fair value											53,267	1,524					346,288	311,993																			12,763	13,519							412,318	327,036
Liabilities:
Other liabilities																			2,606	3,152			16	50																							2,606	3,152			16	50
Liabilities at fair value																	$ 2,622	$ 3,202																											$ 2,622	$ 3,202