CONSOLIDATED STATEMENT OF CHANGES IN EQUITY - 6 months ended Jun. 30, 2017 - USD ($) shares in Thousands, $ in Thousands	Total	Accumulated Deficit	AOCI Attributable to Parent	Common Stock	Additional Paid-in Capital	Treasury Stock
Balance at Dec. 31, 2016	$ 169,777	$ (626,904)	$ (431)	$ 2,157	$ 816,016	$ (21,061)
Balance (in shares) at Dec. 31, 2016				21,573
Balance (in shares) at Dec. 31, 2016						1,209
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(51,194)	(51,194)
Stock options exercised, net of tax withholdings	12				(24)	$ 36
Stock options exercised, net of tax withholdings (in shares)						(2)
Issuance of restricted stock, net of tax withholdings	(45)				(794)	$ 749
Issuance of restricted stock, net of tax withholdings (in shares)						(38)
Stock-based compensation expense	246				246
Repurchase of convertible senior debentures	(677)				(677)
Other comprehensive income	53		53
Balance at Jun. 30, 2017	$ 118,172	$ (678,098)	$ (378)	$ 2,157	$ 814,767	$ (20,276)
Balance (in shares) at Jun. 30, 2017				21,573
Balance (in shares) at Jun. 30, 2017						1,169