Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Common Stock Outstanding [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Total
Balance (in shares) at Dec. 31, 2017	14,688
Balance at Dec. 31, 2017	$ 147	$ 68,617	$ 199,511	$ (4,784)	$ 263,491
Issuance of common stock for equity awards (in shares)	89
Issuance of common stock for equity awards	$ 1	511			512
Retirement of common stock for minimum tax withholdings (in shares)	(32)
Retirement of common stock for minimum tax withholdings	$ (1)	(1,735)			(1,736)
Stock-based compensation expense		7,565			7,565
Net income			(6,686)		(6,686)
Other comprehensive Income (loss)				620	620
Issuance of common stock for equity awards (in shares)	89
Balance (in shares) at Mar. 31, 2018	14,745
Balance at Mar. 31, 2018	$ 147	74,958	192,825	(4,164)	263,766
Balance (in shares) at Dec. 31, 2017	14,688
Balance at Dec. 31, 2017	$ 147	68,617	199,511	(4,784)	263,491
Net income					3,405
Balance (in shares) at Jun. 30, 2018	14,584
Balance at Jun. 30, 2018	$ 146	48,656	202,916	(5,115)	246,603
Balance (in shares) at Mar. 31, 2018	14,745
Balance at Mar. 31, 2018	$ 147	74,958	192,825	(4,164)	263,766
Issuance of common stock for equity awards (in shares)	273
Issuance of common stock for equity awards	$ 3	2,372			2,375
Stock-based compensation expense		1,322			1,322
Net income			10,091		10,092
Other comprehensive Income (loss)				(951)	(951)
Issuance of common stock for equity awards (in shares)	273
Repurchase of common stock (in shares)	(434)
Repurchase of common stock	$ (4)	(29,996)			(30,000)
Balance (in shares) at Jun. 30, 2018	14,584
Balance at Jun. 30, 2018	$ 146	48,656	202,916	(5,115)	246,603
Balance (in shares) at Dec. 31, 2018	14,210
Balance at Dec. 31, 2018	$ 142	50,763	218,233	(5,526)	263,612
Issuance of common stock for equity awards (in shares)	7
Issuance of common stock for equity awards		5			5
Retirement of common stock for minimum tax withholdings (in shares)	(3)
Retirement of common stock for minimum tax withholdings		(124)			(124)
Stock-based compensation expense		1,386			1,386
Net income			4,507		4,507
Other comprehensive Income (loss)				(315)	(315)
Issuance of common stock for equity awards (in shares)	7
Balance (in shares) at Mar. 31, 2019	14,214
Balance at Mar. 31, 2019	$ 142	52,030	222,740	(5,841)	269,071
Balance (in shares) at Dec. 31, 2018	14,210
Balance at Dec. 31, 2018	$ 142	50,763	218,233	(5,526)	263,612
Net income					13,942
Balance (in shares) at Jun. 30, 2019	13,785
Balance at Jun. 30, 2019	$ 138	24,329	232,175	(5,696)	250,946
Balance (in shares) at Mar. 31, 2019	14,214
Balance at Mar. 31, 2019	$ 142	52,030	222,740	(5,841)	269,071
Issuance of common stock for equity awards (in shares)	30
Issuance of common stock for equity awards	$ 1	851			852
Stock-based compensation expense		1,443			1,443
Net income			9,435		9,435
Other comprehensive Income (loss)				145	145
Issuance of common stock for equity awards (in shares)	30
Forfeiture of restricted stock (in shares)	(7)
Forfeiture of restricted stock
Repurchase of common stock (in shares)	(452)
Repurchase of common stock	$ (5)	(29,995)			(30,000)
Balance (in shares) at Jun. 30, 2019	13,785
Balance at Jun. 30, 2019	$ 138	$ 24,329	$ 232,175	$ (5,696)	$ 250,946