Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Total
Balance (in shares) at Dec. 31, 2015	15,037
Balance at Dec. 31, 2015	$ 150	$ 81,685	$ 135,662	$ (6,649)	$ 210,848
Issuance of common stock for equity awards (in shares)	121
Issuance of common stock for equity awards	$ 1	1,006			1,007
Tax benefit related to equity awards		647			647
Stock-based compensation expense		3,392			3,392
Repurchase of common stock (in shares)	(531)
Repurchase of common stock	$ (5)	(24,995)			(25,000)
Net income			32,547		32,547
Other comprehensive Income (loss)				(668)	(668)
Balance (in shares) at Dec. 31, 2016	14,627
Balance at Dec. 31, 2016	$ 146	61,735	168,209	(7,317)	222,773
Issuance of common stock for equity awards (in shares)	61
Issuance of common stock for equity awards	$ 1	313			314
Stock-based compensation expense		5,807			5,807
Net income			31,816		31,816
Other comprehensive Income (loss)				2,533	2,533
Balance (in shares) at Dec. 31, 2017	14,688
Balance at Dec. 31, 2017	$ 147	68,617	199,511	(4,784)	263,491
Cumulative effect of change in accounting for stock-based compensation		762	(514)		248
Issuance of common stock for equity awards (in shares)	362
Issuance of common stock for equity awards	$ 4	2,882			2,886
Stock-based compensation expense		11,046			11,046
Repurchase of common stock (in shares)	(806)
Repurchase of common stock	$ (8)	(29,992)			(30,000)
Net income			18,722		18,722
Other comprehensive Income (loss)				(742)	(742)
Retirement of common stock for minimum tax withholdings (in shares)	(34)
Retirement of common stock for minimum tax withholdings	$ (1)	(1,790)			(1,791)
Balance (in shares) at Dec. 31, 2018	14,210
Balance at Dec. 31, 2018	$ 142	$ 50,763	$ 218,233	$ (5,526)	$ 263,612