|
Fair Value Measurements (Details) (USD $)
|
12 Months Ended | 12 Months Ended | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Dec. 31, 2013
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2013
Preferred stock warrants
|
Dec. 31, 2012
Preferred stock warrants
|
Aug. 07, 2013
Preferred stock warrants
|
Dec. 31, 2012
Redeemable preferred stock warrants
|
Dec. 31, 2013
Measured on a recurring basis
Level 1
Money market funds
|
Dec. 31, 2012
Measured on a recurring basis
Level 1
Money market funds
|
Dec. 31, 2012
Measured on a recurring basis
Level 3
Redeemable preferred stock warrants
|
Dec. 31, 2012
Measured on a recurring basis
Total
Redeemable preferred stock warrants
|
Dec. 31, 2013
Measured on a recurring basis
Total
Money market funds
|
Dec. 31, 2012
Measured on a recurring basis
Total
Money market funds
|
|
| Assumptions used for calculation of fair value of the warrant | |||||||||||||
| Dividend yield (as a percent) | 0.00% | ||||||||||||
| Expected volatility (as a percent) | 54.00% | ||||||||||||
| Risk-free interest rate (as a percent) | 0.16% | ||||||||||||
| Remaining contractual term | 1 year 6 months | ||||||||||||
| Fair value | |||||||||||||
| Cash equivalents | $ 79,013,000 | $ 15,554,000 | $ 79,013,000 | $ 15,554,000 | |||||||||
| Other liabilities | 601,000 | 601,000 | |||||||||||
| Change in fair value of warrant liability recorded in other expense | 709,000 | 254,000 | (227,000) | 300,000 | 700,000 | ||||||||
| Aggregate fair value of warrant liability | $ 1,300,000 | ||||||||||||