Condensed Financial Information - Parent Company Only - Balance Sheet (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
ASSETS
Cash and due from banks	$ 98,399	$ 39,857	$ 11,624	$ 20,535
Investments in subsidiaries, at equity in net assets:
Other assets	624	624
Total assets	2,304,841	2,206,839
LIABILITIES
Subordinated capital notes	375	1,875
Junior Subordinated Debenture Owed to Unconsolidated Subsidiary Trust	20,619	20,619
Total liabilities	2,020,564	1,933,860
Shareholders' equity	284,277	272,979	266,224	267,807
Total liabilities and shareholders' equity	2,304,841	2,206,839
Parent Company [Member]
ASSETS
Cash and due from banks	12,556	2,554	648	86
Investments in securities	2,842	5,208
Investments in subsidiaries, at equity in net assets:
Bank	277,107	276,405
Non-banks	15,020	16,126
Other assets	19,659	27,126
Total assets	327,184	327,419
LIABILITIES
Dividends payable		3,344
Other borrowings		332
Subordinated capital notes	375	1,875
Junior Subordinated Debenture Owed to Unconsolidated Subsidiary Trust	20,619	20,619
Other liabilities	21,913	28,270
Total liabilities	42,907	54,440
Shareholders' equity	284,277	272,979
Total liabilities and shareholders' equity	$ 327,184	$ 327,419