Summarized Quarterly Data (Unaudited) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 9,496	$ 8,453	$ 8,030	$ 18,347	$ 7,901	$ 10,398	$ 10,237	$ 9,040	$ 44,326	$ 37,576	$ 23,442
Cost of sales	6,018	4,249	4,167	5,062	4,961	5,482	3,975	4,875	19,496	19,293	12,846
Gross profit	3,478	4,204	3,863	13,285	2,940	4,916	6,262	4,165
Net loss	$ (643)	$ (19,282)	$ (17,169)	$ (10,292)	$ (23,705)	$ (22,038)	$ (19,177)	$ (18,983)	$ (47,386)	$ (83,903)	$ (73,564)
Net loss per share, basic and diluted, USD per share	$ (0.01)	$ (0.21)	$ (0.26)	$ (0.16)	$ (0.36)	$ (0.59)	$ (0.56)	$ (0.56)	$ (0.59)	$ (1.96)	$ (17.63)
Weighted average shares outstanding, basic and diluted, in shares	100,714	90,370	65,449	65,369	65,215	37,320	34,018	33,973	80,558	42,712	4,173