The Company's effective income tax rate differed from the federal statutory rate as follows (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
The Company's effective income tax rate differed from the federal statutory rate as follows
U.S. Federal statutory tax rate	(35.00%)	(35.00%)	(35.00%)
Deferred state taxes, net of federal benefit	(1.30%)	(3.30%)	(3.10%)
Common stock warrant liability	20.60%	(5.30%)	(4.40%)
Gain on Hypulsion transaction	(1.80%)	0.00%	0.00%
Other, net	0.10%	0.10%	0.60%
Change to uncertain tax positions	(1.30%)	(1.60%)	(57.50%)
Foreign tax rate differential	0.20%	0.50%	0.80%
Expiring attribute carryforward	2.20%	0.00%	5.40%
Adjustments to open deferred tax balance	(0.30%)	(5.80%)	(1.70%)
Writeoff of tax attributes due to imposition of Section 382 limitation	1.50%	165.70%	840.90%
Tax credits	0.00%	0.00%	(0.30%)
Change in valuation allowance	14.50%	(115.30%)	(745.70%)
Effective income tax rate reconciliation	(0.60%)	0.00%	0.00%