Unaudited Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common stock	Additional paid-in capital	Accumulated deficit	Accumulated other comprehensive loss	Treasury stock
Balance (in shares) at Mar. 31, 2020		49,148				1,306
Balance at Dec. 31, 2019	$ 643,515	$ 5	$ 1,586,972	$ (914,791)	$ (272)	$ (28,399)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued for stock options, restricted stock units (in shares)		89
Common stock issued for stock options and restricted stock units	0
Stock-based compensation	(1,201)		(1,201)
Tax payments from shares withheld for equity awards	(917)		(917)
Cumulative translation adjustment	272				272
Net income (loss)	(315,494)			(315,494)
Balance (in shares) at Dec. 31, 2019		49,059				1,306
Balance at Mar. 31, 2020	326,175	$ 5	1,584,854	(1,230,285)	0	$ (28,399)
Balance (in shares) at Mar. 31, 2021		49,615				1,306
Balance at Dec. 31, 2020	312,290	$ 5	1,598,230	(1,257,546)	0	$ (28,399)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued for stock options, restricted stock units (in shares)		132
Common stock issued for stock options and restricted stock units	63		63
Stock-based compensation	5,520		5,520
Tax payments from shares withheld for equity awards	(865)		(865)
Cumulative translation adjustment	0
Net income (loss)	27,646			27,646
Balance (in shares) at Dec. 31, 2020		49,483				1,306
Balance at Mar. 31, 2021	$ 344,654	$ 5	$ 1,602,948	$ (1,229,900)	$ 0	$ (28,399)