Condensed Consolidated Statements of Shareholders' Equity (USD $) In Thousands, unless otherwise specified	Total	Parent [Member]	Preferred Stock [Member]	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance at Dec. 31, 2011		$ 239,565	$ 33,293	$ 178	$ (1,743)	$ 169,138	$ 35,097	$ 3,602
Net Income (Loss) Available to Common Stockholders, Basic	13,666	14,951	0	0	0	0	14,951	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	14,951
Change in fair value of available for sale securities, net of tax	3,278
Reclassification adjustment for realized gain on sale of securities included in net income, net of tax	(740)
Total comprehensive income	17,489	2,538	0	0	0	0	0	2,538
Cash dividends paid on common shares, $0.1575 per share		(1,871)	0	0	0	0	(1,871)	0
Cash dividends paid on preferred stock		(875)	0	0	0	0	(875)	0
Preferred stock accretion of discount		0	410	0	0	0	(410)	0
Issuance under equity compensation plans, net		456	0	1	0	455	0	0
Share-based compensation		1,124	0	0	0	1,124	0	0
Balance at Jun. 30, 2012		255,888	33,703	179	(1,743)	170,717	46,892	6,140
Balance at Dec. 31, 2012	235,745	235,745	0	181	(1,743)	173,299	56,218	7,790
Net Income (Loss) Available to Common Stockholders, Basic	21,073	21,073	0	0	0	0	21,073	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	21,073
Change in fair value of available for sale securities, net of tax	(9,920)
Reclassification adjustment for realized gain on sale of securities included in net income, net of tax	(417)
Total comprehensive income	10,736	(10,337)	0	0	0	0	0	(10,337)
Cash dividends paid on common shares, $0.1575 per share		(1,904)	0	0	0	0	(1,904)	0
Repurchase of common stock warrants		(1,006)	0	0	0	(1,006)	0	0
Issuance under equity compensation plans, net		2,264	0	2	0	2,262	0	0
Share-based compensation		1,788	0	0	0	1,788	0	0
Excess tax benefit related to equity compensation plans		52	0	0	0	52	0	0
Balance at Jun. 30, 2013	$ 247,675	$ 247,675	$ 0	$ 183	$ (1,743)	$ 176,395	$ 75,387	$ (2,547)