Condensed Consolidated Statements of Changes in Stockholders' Equity - 3 months ended Mar. 31, 2017 - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Balances at Dec. 31, 2016	$ 768,487	$ 1,809	$ 3,314,590	$ (2,545,424)	$ (2,488)
Balances, in shares at Dec. 31, 2016		180,933
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	18,663			18,663
Other comprehensive income (loss)	(590)				(590)
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures		560
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures	60	$ 6	54
Balances at Mar. 31, 2017	$ 786,620	$ 1,815	$ 3,314,644	$ (2,526,761)	$ (3,078)
Balances, in shares at Mar. 31, 2017		181,493