Condensed Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]
Beginning balance at Dec. 31, 2014	$ 418,172	$ 244,318	$ 176,057	$ (2,203)
Beginning balance, shares at Dec. 31, 2014		22,714,964
Net income	8,336		8,336
Other comprehensive income	120			120
Stock option vesting	220	$ 220
RSU vesting	76	76
PSU vesting	28	28
Stock options exercised	887	$ 887
Stock options exercised, shares		47,000
Tax benefit of stock options exercised	18	$ 18
Repurchase of common stock	(509)	$ (231)	(278)
Repurchase of common stock, shares		(21,461)
Dividends paid	(2,515)		(2,515)
Ending balance at Mar. 31, 2015	424,833	$ 245,316	181,600	(2,083)
Ending balance, shares at Mar. 31, 2015		22,740,503
Beginning balance at Dec. 31, 2015	$ 452,116	$ 247,587	206,307	(1,778)
Beginning balance, shares at Dec. 31, 2015	22,775,173	22,775,173
Net income	$ 10,674		10,674
Other comprehensive income	3,550			3,550
Stock option vesting	155	$ 155
RSU vesting	120	120
PSU vesting	56	56
Stock options exercised	$ 173	$ 173
Stock options exercised, shares	10,000	10,000
Tax benefit of stock options exercised	$ 10	$ 10
Dividends paid	(3,418)		(3,418)
Ending balance at Mar. 31, 2016	$ 463,436	$ 248,101	$ 213,563	$ 1,772
Ending balance, shares at Mar. 31, 2016	22,785,173	22,785,173