Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in-Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]
Beginning Balance at Dec. 31, 2017	$ 239,411	$ 1,321	$ 94,384	$ 168,752	$ (25,046)
Beginning Balance, shares at Dec. 31, 2017		13,205
Issuance of restricted stock awards		$ 10	(10)
Issuance of restricted stock awards, shares		97
Exercise of stock options	8	$ 8
Exercise of stock options, shares		89
Shares withheld related to net share settlement	(515)	$ (6)	(509)
Shares withheld related to net share settlement, shares		(57)
Share-based compensation	2,504		2,504
Net income	17,126			17,126
Ending Balance at Jun. 30, 2018	258,534	$ 1,333	96,369	185,878	(25,046)
Ending Balance, shares at Jun. 30, 2018		13,334
Beginning Balance at Mar. 31, 2018	248,951	$ 1,329	95,272	177,396	(25,046)
Beginning Balance, shares at Mar. 31, 2018		13,294
Issuance of restricted stock awards		$ 3	(3)
Issuance of restricted stock awards, shares		29
Exercise of stock options	2	$ 2
Exercise of stock options, shares		29
Shares withheld related to net share settlement	(197)	$ (1)	(196)
Shares withheld related to net share settlement, shares		(18)
Share-based compensation	1,296		1,296
Net income	8,482			8,482
Ending Balance at Jun. 30, 2018	258,534	$ 1,333	96,369	185,878	(25,046)
Ending Balance, shares at Jun. 30, 2018		13,334
Beginning Balance at Dec. 31, 2018	279,161	$ 1,332	98,778	204,097	(25,046)
Beginning Balance, shares at Dec. 31, 2018		13,323
Issuance of restricted stock awards		$ 19	(19)
Issuance of restricted stock awards, shares		190
Repurchase of common stock	$ (7,144)				(7,144)
Exercise of stock options, shares	0
Shares withheld related to net share settlement	$ (467)	$ (2)	(465)
Shares withheld related to net share settlement, shares		(19)
Share-based compensation	2,192		2,192
Net income	16,477			16,477
Ending Balance at Jun. 30, 2019	290,219	$ 1,349	100,486	220,574	(32,190)
Ending Balance, shares at Jun. 30, 2019		13,494
Beginning Balance at Mar. 31, 2019	287,816	$ 1,347	99,310	212,205	(25,046)
Beginning Balance, shares at Mar. 31, 2019		13,465
Issuance of restricted stock awards		$ 3	(3)
Issuance of restricted stock awards, shares		29
Repurchase of common stock	(7,144)				(7,144)
Shares withheld related to net share settlement	(17)	$ (1)	(16)
Share-based compensation	1,195		1,195
Net income	8,369			8,369
Ending Balance at Jun. 30, 2019	$ 290,219	$ 1,349	$ 100,486	$ 220,574	$ (32,190)
Ending Balance, shares at Jun. 30, 2019		13,494