Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	AOCI Attributable to Parent [Member]	Total
Balance (in shares) at Dec. 31, 2012	31,704,230
Balance at Dec. 31, 2012	$ 3,169	$ 104,173	$ 105,263	$ (15,217)	$ (34,091)	$ 163,297
Net income			$ 25,915			25,915
Other comprehensive Income (loss)					$ 15,129	15,129
Exercise of stock options (in shares)	536,565
Exercise of stock options	$ 54	$ 3,170				$ 3,224
Vested restricted stock		(534)		$ 534
Stock option expense		1,994				$ 1,994
Restricted stock expense		427				427
Performance stock expense		404				404
Share based compensation tax windfall		$ 131				131
Repurchase of shares				$ (301)		(301)
Balance (in shares) at Dec. 31, 2013	32,240,795
Balance at Dec. 31, 2013	$ 3,223	$ 109,765	$ 131,178	$ (14,984)	$ (18,962)	210,220
Net income			$ 57,303			57,303
Other comprehensive Income (loss)					$ (26,019)	(26,019)
Exercise of stock options (in shares)	596,135
Exercise of stock options	$ 61	$ 4,142				$ 4,203
Vested restricted stock		(161)		$ 161
Stock option expense		2,491				$ 2,491
Restricted stock expense		395				395
Performance stock expense		2,116				2,116
Share based compensation tax windfall		517				$ 517
Balance (in shares) at Dec. 31, 2014	32,836,930					32,836,930
Balance at Dec. 31, 2014	$ 3,284	$ 119,265	$ 188,481	$ (14,823)	$ (44,981)	$ 251,226
Net income			$ 57,217			57,217
Other comprehensive Income (loss)					$ (10,468)	(10,468)
Exercise of stock options (in shares)	691,985
Exercise of stock options	$ 69	$ 5,747				$ 5,816
Vested restricted stock		(76)		$ 76
Stock option expense		2,975				$ 2,975
Restricted stock expense		353				353
Performance stock expense		2,271				2,271
Share based compensation tax windfall		1,445				$ 1,445
Balance (in shares) at Dec. 31, 2015	33,528,915					33,528,915
Balance at Dec. 31, 2015	$ 3,353	$ 131,980	$ 245,698	$ (14,747)	$ (55,449)	$ 310,835