CONSOLIDATED STATEMENT OF CHANGES IN EQUITY - 6 months ended Jun. 30, 2018 - 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, 2017	$ 81,796	$ (715,476)	$ (113)	$ 2,157	$ 812,536	$ (17,308)
Balance (in shares) at Dec. 31, 2017				21,573
Balance (in shares) at Dec. 31, 2017						999
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(31,066)	(31,066)
Stock options exercised, net of tax withholdings	0				(16)	$ 16
Stock options exercised, net of tax withholdings (in shares)						1
Issuance of restricted stock, net of tax withholdings	(200)				(2,041)	$ 1,841
Issuance of restricted stock, net of tax withholdings (in shares)						(75)
Stock-based compensation expense	610				610
Other comprehensive income	81		81
Balance at Jun. 30, 2018	$ 51,221	$ (746,542)	$ (32)	$ 2,157	$ 811,089	$ (15,451)
Balance (in shares) at Jun. 30, 2018				21,573
Balance (in shares) at Jun. 30, 2018						923