Net Loss per Share (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded as anti-dilutive	6,670	7,189	6,670	7,189
Stock options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded as anti-dilutive	6,595	7,114	6,595	7,114
Warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded as anti-dilutive	75	75	75	75