Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings
Beginning balance (in shares) at Dec. 31, 2018		16,425
Beginning balance at Dec. 31, 2018	$ 321,266	$ 164	$ 187,172	$ 133,930
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under employee benefit plans (in shares)		251
Issuance of common stock under employee benefit plans	0	$ 3	(3)
Deemed repurchased shares of common and restricted stock for tax withholding (in shares)		(83)
Deemed repurchased shares of common and restricted stock for tax withholding	(2,510)	$ (1)	(2,509)
Stock-based compensation	3,319		3,319
Repurchased and retired shares of common stock (in shares)		(327)
Repurchased and retired shares of common stock	(9,551)	$ (3)		(9,548)
Net income	5,932			5,932
Ending balance (in shares) at Jun. 30, 2019		16,266
Ending balance at Jun. 30, 2019	318,456	$ 163	187,979	130,314
Beginning balance (in shares) at Dec. 31, 2019		15,178
Beginning balance at Dec. 31, 2019	296,733	$ 152	190,620	105,961
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under employee benefit plans (in shares)		240
Issuance of common stock under employee benefit plans	0	$ 2	(2)
Deemed repurchased shares of common and restricted stock for tax withholding (in shares)		(73)
Deemed repurchased shares of common and restricted stock for tax withholding	(1,946)	$ (1)	(1,945)
Stock-based compensation	3,323		3,323
Repurchased and retired shares of common stock (in shares)		(548)
Repurchased and retired shares of common stock	(13,608)	$ (5)		(13,603)
Net income	9,109			9,109
Ending balance (in shares) at Jun. 30, 2020		14,797
Ending balance at Jun. 30, 2020	$ 293,611	$ 148	$ 191,996	$ 101,467