CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Accumulated Deficit [Member]	AOCI Attributable to Parent [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Treasury Stock [Member]
Beginning Balance at Dec. 31, 2016	$ 169,777	$ (626,904)	$ (431)	$ 2,157	$ 816,016	$ (21,061)
Beginning Balance (in shares) at Dec. 31, 2016				21,573		1,209
Net loss	(88,572)	(88,572)
Stock options exercised, net of tax withholdings	(1)				(97)	$ 96
Stock options exercised, net of tax withholdings (in shares)						6
Issuance of restricted stock, net of tax withholdings	(38)				(3,695)	$ 3,657
Issuance of restricted stock, net of tax withholdings (in shares)						(204)
Stock-based compensation expense	1,138				1,138
Repurchase of convertible senior debentures	(826)				(826)
Other comprehensive income	318		318
Ending Balance at Dec. 31, 2017	81,796	(715,476)	(113)	$ 2,157	812,536	$ (17,308)
Ending Balance (in shares) at Dec. 31, 2017				21,573		999
Net loss	(15,629)	(15,629)
Stock options exercised, net of tax withholdings	0				(16)	$ 16
Stock options exercised, net of tax withholdings (in shares)						0
Issuance of restricted stock, net of tax withholdings	(267)				(2,558)	$ 2,291
Issuance of restricted stock, net of tax withholdings (in shares)						(85)
Stock-based compensation expense	966				966
Other comprehensive income	113		113
Ending Balance at Dec. 31, 2018	$ 66,979	$ (731,105)	$ 0	$ 2,157	$ 810,928	$ (15,001)
Ending Balance (in shares) at Dec. 31, 2018				21,573		914