Summary of Significant Accounting Policies - Additional Information (Details) |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2015
USD ($)
segment
|
Dec. 31, 2014
USD ($)
|
Dec. 31, 2013
USD ($)
|
|
| Accounting Policies [Abstract] | |||
| Number of operating segments | segment | 1 | ||
| Number of reportable segments | segment | 1 | ||
| Held-to-maturity securities, current | $ 1,000,000 | ||
| Restricted cash | 1,500,000 | $ 1,500,000 | |
| Decrease in goodwill | 200,000 | ||
| Goodwill | 0 | 200,000 | |
| Asset impairment | $ 0 | $ 0 | $ 0 |