Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ 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, 2013	19,765			853
Balance at Dec. 31, 2013	$ 21	$ 250,698	$ 245,907	$ (21,545)	$ (990)	$ 474,091
Net income			40,030			40,030
Other comprehensive loss					(1,491)	(1,491)
Equity compensation		10,680		$ 328		11,008
Exercise of stock options (in shares)	85
Exercise of stock options		$ 1,831				$ 1,831
Issuance of shares pursuant to vesting of restricted stock units (in shares)	333
Net payments for stock issuances and buybacks (in shares)	(753)	3,543		753		3,543
Net payments for stock issuances and buybacks		$ 454		$ (28,777)		$ (28,323)
Tax impact of stock option exercises and award vesting (in shares)	(753)	3,543		753		3,543
Balance (in shares) at Dec. 31, 2014	19,430			1,606
Balance at Dec. 31, 2014	$ 21	$ 267,206	285,937	$ (49,994)	(2,481)	$ 500,689
Other comprehensive loss					(1,491)	(1,491)
Net income			39,369			39,369
Other comprehensive loss					(5,010)	(5,010)
Equity compensation		10,392		$ 458		10,850
Exercise of stock options (in shares)	44
Exercise of stock options		932				932
Issuance of shares pursuant to vesting of restricted stock units (in shares)	234
Net payments for stock issuances and buybacks (in shares)	(676)			676
Net payments for stock issuances and buybacks		276		$ (25,137)		(24,861)
Tax impact of stock option exercises and award vesting (in shares)	(676)			676
Balance (in shares) at Dec. 31, 2015	19,032			2,282
Balance at Dec. 31, 2015	$ 21	280,113	325,306	$ (74,673)	(7,491)	523,276
Tax impact of stock option exercises and award vesting		1,307				1,307
Other comprehensive loss					(5,010)	(5,010)
Net income			46,584			46,584
Other comprehensive loss					(2,149)	(2,149)
Equity compensation		8,734		$ 348		9,082
Exercise of stock options (in shares)	128
Exercise of stock options	$ 1	3,033				3,034
Issuance of shares pursuant to vesting of restricted stock units (in shares)	221
Net payments for stock issuances and buybacks (in shares)	(360)			360
Net payments for stock issuances and buybacks		547		$ (14,370)		(13,823)
Tax impact of stock option exercises and award vesting (in shares)	(360)			360
Balance (in shares) at Dec. 31, 2016	19,021			2,642
Balance at Dec. 31, 2016	$ 22	$ 292,427	$ 371,890	$ (88,695)	(9,640)	566,004
Other comprehensive loss					$ (2,149)	$ (2,149)