Condensed Consolidated Statements of Changes in Stockholders' Equity - 9 months ended Sep. 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)	(8,944)			(8,944)
Other comprehensive income (loss)	592				592
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures		496
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures	4,402	$ 5	4,397
Balances at Sep. 30, 2017	$ 764,537	$ 1,814	$ 3,318,987	$ (2,554,368)	$ (1,896)
Balances, in shares at Sep. 30, 2017		181,429