Condensed Consolidated Statements of Changes in Stockholders' Equity - 6 months ended Jun. 30, 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)	7,708			7,708
Other comprehensive income (loss)	(506)				(506)
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures		509
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures	1,822	$ 5	1,817
Balances at Jun. 30, 2017	$ 777,511	$ 1,814	$ 3,316,407	$ (2,537,716)	$ (2,994)
Balances, in shares at Jun. 30, 2017		181,442