Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) shares in Thousands, $ in Thousands	Total	Common Shares [Member]	Capital in Excess of Par Value [Member]	Accumulated Other Comprehensive Income/(Loss) [Member]	Accumulated Deficit [Member]
Beginning Balance at Dec. 31, 2012	$ 47,018	$ 11	$ 1,617,744	$ (357)	$ (1,570,380)
Beginning Balance, Shares at Dec. 31, 2012		115,259
Shares issued under equity compensation plans	8,208	$ 0	8,208	0	0
Shares issued under equity compensation plans, Shares		1,235
Stock-based compensation	17,708	$ 0	17,708	0	0
Other comprehensive loss	(824)	0	0	(824)	0
Net loss	(162,013)	0	0	0	(162,013)
Ending Balance at Dec. 31, 2013	(89,903)	$ 11	1,643,660	(1,181)	(1,732,393)
Ending Balance, Shares at Dec. 31, 2013		116,494
Sale of common stock, net of issuance costs of $617	116,536	$ 1	116,535	0	0
Sale of common stock, Shares		9,775
Shares issued under equity compensation plans	46,984	$ 1	46,983	0	0
Shares issued under equity compensation plans, Shares		4,947
Stock-based compensation	17,017	$ 0	17,017	0	0
Other comprehensive loss	(386)	0	0	(386)	0
Net loss	(53,916)	0	0	0	(53,916)
Ending Balance at Dec. 31, 2014	36,332	$ 13	1,824,195	(1,567)	(1,786,309)
Ending Balance, Shares at Dec. 31, 2014		131,216
Shares issued under equity compensation plans	32,208	$ 0	32,208	0	0
Shares issued under equity compensation plans, Shares		4,073
Stock-based compensation	19,669	$ 0	19,669	0	0
Other comprehensive loss	(603)	0	0	(603)	0
Net loss	(81,177)	0	0	0	(81,177)
Ending Balance at Dec. 31, 2015	$ 6,429	$ 13	$ 1,876,072	$ (2,170)	$ (1,867,486)
Ending Balance, Shares at Dec. 31, 2015		135,289