Condensed Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Treasury [Member]	Additional Paid In Capital [Member]	Retained Earnings [Member]
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Treasury Stock, Shares			(877,000)
Common stock, shares, outstanding at Dec. 31, 2019		80,079,000
Beginning Balance, value at Dec. 31, 2019	$ 104,076	$ 8,008	$ (5,090)	$ 553,210	$ (452,052)
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Net loss	(69,104)				(69,104)
Purchase of treasury stock, shares			(165,000)
Purchase of treasury stock, value	(7)		$ (7)
Equity awards vested or exercised, shares		542,000
Equity awards vested, issued, or exercised, value		$ (54)		54
Stock-based compensation expense	328			328
Common stock, shares, outstanding at Mar. 31, 2020		80,621,000
Ending Balance, value at Mar. 31, 2020	$ 35,293	$ 8,062	$ (5,097)	553,484	(521,156)
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Treasury Stock, Shares			(1,042,000)
Treasury Stock, Shares			(1,000)
Common stock, shares, outstanding at Dec. 31, 2020	1,647,224	1,649,000
Beginning Balance, value at Dec. 31, 2020	$ 101,897	$ 2	$ 0	142,119	(40,224)
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Net loss	(16,942)				(16,942)
Stock-based compensation expense	$ 830			830
Common stock, shares, outstanding at Mar. 31, 2021	1,647,224	1,649,000
Ending Balance, value at Mar. 31, 2021	$ 85,785	$ 2	$ 0	$ 142,949	$ (57,166)
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Treasury Stock, Shares			(1,000)