Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Numerator [Abstract]
Net loss - numerator for basic loss per share	$ (9,596)		$ (3,949)
Denominator [Abstract]
Shares used for basic loss per share (in shares)	35,151		34,018
Shares used for diluted loss per share (in shares)	35,151	[1]	34,018	[1]
Loss per share [Abstract]
Basic (in dollars per share)	$ (0.27)		$ (0.12)
Diluted (in dollars per share)	$ (0.27)	[1]	$ (0.12)	[1]
Non-Qualified Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive securities outstanding not included in the computation of loss per share because their effect is antidilutive (in shares)	2,571		4,276
Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive securities outstanding not included in the computation of loss per share because their effect is antidilutive (in shares)	332		489
Warrants Related to Cash Convertible Notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive securities outstanding not included in the computation of loss per share because their effect is antidilutive (in shares)	7,707		0
CareFirst Convertible Note [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive securities outstanding not included in the computation of loss per share because their effect is antidilutive (in shares)	892		0
Non-Qualified Stock Options [Member]
Denominator [Abstract]
Effect of dilutive stock options and restricted stock units outstanding (in shares)	0	[1]	0	[1]
Restricted Stock Units [Member]
Denominator [Abstract]
Effect of dilutive stock options and restricted stock units outstanding (in shares)	0	[1]	0	[1]

[1] The assumed exercise of stock-based compensation awards for the three months ended March 31, 2014 and 2013 was not considered because the impact would be anti-dilutive.