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			(631,000)
Common stock, shares, outstanding at Dec. 31, 2017		78,350,000
Beginning Balance, value at Dec. 31, 2017	$ 210,096	$ 7,835	$ (4,416)	$ 546,158	$ (339,481)
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Net loss	(49,011)				(49,011)
Exercise of options and related income tax effect, shares		3,000
Exercise of options and related income tax effect, value	12	$ 0		12
Purchase of treasury stock, shares			(159,000)
Purchase of treasury stock, value	(549)		$ (549)
Issuance of restricted stock, shares		651,000
Issuance of restricted stock, value		$ 65		(65)
Stock-based compensation expense	4,443			4,443
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 67
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification | Accounting Standards Update 2014-09 [Member]					67
Common stock, shares, outstanding at Dec. 31, 2018	78,214,550	79,004,000
Ending Balance, value at Dec. 31, 2018	$ 165,058	$ 7,900	$ (4,965)	550,548	(388,425)
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Treasury Stock, Shares			(790,000)
Net loss	(63,904)				(63,904)
Purchase of treasury stock, shares			(87,000)
Purchase of treasury stock, value	(125)		$ (125)
Issuance of restricted stock, shares		1,075,000
Issuance of restricted stock, value		$ 108		(108)
Stock-based compensation expense	2,770			2,770
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 277
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification | Accounting Standards Update 2016-02 [Member]					277
Common stock, shares, outstanding at Dec. 31, 2019	79,202,216	80,079,000
Ending Balance, value at Dec. 31, 2019	$ 104,076	$ 8,008	$ (5,090)	$ 553,210	$ (452,052)
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Treasury Stock, Shares			(877,000)