Condensed Consolidated Statements of Shareholders' Equity (USD $) In Thousands, unless otherwise specified	Total	Preferred Stock	Common Stock	Treasury Stock	Additional paid in capital	Retained earnings	Accumulated Other Comprehensive Income (Loss) [Member]	Total shareholders' equity
Balance at Dec. 31, 2012		$ 0	$ 181	$ (1,743)	$ 173,299	$ 56,218	$ 7,790	$ 235,745
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	29,483	0	0	0	0	29,483	0	29,483
Other comprehensive income	(9,771)	0	0	0	0	0	(9,771)	(9,771)
Cash dividends paid on common shares		0	0	0	0	(2,924)	0	(2,924)
Repurchase of common stock warrants		0	0	0	(1,006)	0	0	(1,006)
Issuance under equity compensation plans		0	1	0	2,550	0	0	2,551
Trust preferred securities conversion 287,852 shares	20,443	0	12	0	20,431	0	0
Share-based compensation		0	0	0	3,136	0	0	3,136
Excess tax benefit related to equity compensation plans		0	0	0	83	0	0	83
Balance at Sep. 30, 2013		0	194	(1,743)	198,493	82,777	(1,981)	277,740
Balance at Dec. 31, 2013	279,705	0	194	(1,743)	200,258	85,376	(4,380)	279,705
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	21,206	0	0	0	0	21,206	0	21,206
Other comprehensive income	4,147	0	0	0	0	0	4,147	4,147
Cash dividends paid on common shares		0	0	0	0	(3,130)	0	(3,130)
Issuance under equity compensation plans		0	2	0	(484)	0	0	(482)
Trust preferred securities conversion 287,852 shares	5,002	0	3	0	4,999	0	0	5,002
Share-based compensation		0	0	0	2,205	0	0	2,205
Excess tax benefit related to equity compensation plans		0	0	0	101	0	0	101
Balance at Sep. 30, 2014	$ 308,754	$ 0	$ 199	$ (1,743)	$ 207,079	$ 103,452	$ (233)	$ 308,754