Consolidated Statements of Changes in Shareholders' Equity (USD $) In Thousands, unless otherwise specified	Preferred Stock [Member]	Common Stock [Member]	Warrant [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balances at Dec. 31, 2011	$ 56,600	$ 197	$ 946	$ 132,670	$ 71,423	$ 4,875	$ 266,711
Net Income					7,633		7,633
Net change in other comprehensive income						22	22
Stock-based compensation				1,187	(1)		1,186
Common stock issued under equity compensation plans		2		435	(1)		436
Tax benefits related to non-qualified stock compensation				19	(2)		17
Employee stock purchase plan				144			144
Preferred stock:
Preferred stock dividends					(141)		(141)
Balances at Mar. 31, 2012	56,600	199	946	134,455	78,911	4,897	276,008
Balances at Dec. 31, 2012	56,600	226	946	180,593	106,146	5,465	349,976
Net Income					11,572		11,572
Net change in other comprehensive income						(957)	(957)
Stock-based compensation				710			710
Common stock issued under equity compensation plans		2		467			469
Tax benefits related to non-qualified stock compensation				134			134
Employee stock purchase plan				89			89
Preferred stock:
Preferred stock dividends					(141)		(141)
Balances at Mar. 31, 2013	$ 56,600	$ 228	$ 946	$ 181,993	$ 117,577	$ 4,508	$ 361,852