CONSOLIDATED STATEMENT OF SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Treasury Stock
Beginning balance at Dec. 31, 2019	$ 402,326	$ 157	$ 1,177,984	$ (592,654)	$ (183,161)
Beginning balance (in shares) at Dec. 31, 2019		15,677			2,641
Increase (Decrease) in Stockholders' Equity
Net income and comprehensive income	14,401			14,401
Non-cash compensation	11,917		11,917
Issuance of common stock for stock options, restricted stock awards and restricted stock units, net of withholding taxes	(5,087)	$ 0	(5,087)
Issuance of common stock for stock options, restricted stock awards and restricted stock units, net of withholding taxes (in shares)		27
Other	0		(1)	1
Ending balance at Mar. 31, 2020	423,557	$ 157	1,184,813	(578,252)	$ (183,161)
Ending balance (in shares) at Mar. 31, 2020		15,704			2,641
Beginning balance at Dec. 31, 2020	364,761	$ 158	1,188,673	(640,909)	$ (183,161)
Beginning balance (in shares) at Dec. 31, 2020		15,766			2,641
Increase (Decrease) in Stockholders' Equity
Net income and comprehensive income	19,049			19,049
Non-cash compensation	16,436		16,436
Issuance of common stock for stock options, restricted stock awards and restricted stock units, net of withholding taxes	(4,801)		(4,801)
Issuance of common stock for stock options, restricted stock awards and restricted stock units, net of withholding taxes (in shares)		31
Other	(2)		(2)
Ending balance at Mar. 31, 2021	$ 395,443	$ 158	$ 1,200,306	$ (621,860)	$ (183,161)
Ending balance (in shares) at Mar. 31, 2021		15,797			2,641