Net Loss per Share (Details) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded as anti-dilutive	6,473	6,545	6,473	6,545
Stock options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded as anti-dilutive	3,674	4,805	3,674	4,805
Restricted stock units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded as anti-dilutive	1,950	1,665	1,950	1,665
Performance stock units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded as anti-dilutive	774	0	774	0
Warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded as anti-dilutive	75	75	75	75