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)		252
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	5,031		5,031
Repurchased and retired shares of common stock (in shares)		(966)
Repurchased and retired shares of common stock	(27,303)	$ (10)		(27,293)
Net income	4,294			4,294
Ending balance (in shares) at Sep. 30, 2019		15,628
Ending balance at Sep. 30, 2019	300,778	$ 156	189,691	110,931
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)		258
Issuance of common stock under employee benefit plans	0	$ 2	(2)
Deemed repurchased shares of common and restricted stock for tax withholding (in shares)		(79)
Deemed repurchased shares of common and restricted stock for tax withholding	(2,097)	$ (1)	(2,096)
Stock-based compensation	5,265		5,265
Repurchased and retired shares of common stock (in shares)		(548)
Repurchased and retired shares of common stock	(13,608)	$ (5)		(13,603)
Net income	11,751			11,751
Ending balance (in shares) at Sep. 30, 2020		14,809
Ending balance at Sep. 30, 2020	$ 298,044	$ 148	$ 193,787	$ 104,109