Income Taxes - Roll Forward of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] | |||
| Gross unrecognized tax benefits at the beginning of the year | $ 7,214 | $ 4,513 | $ 2,445 |
| Increases for tax positions of prior years | 133 | 871 | 0 |
| Decreases for tax positions of prior years | (346) | (831) | 0 |
| Increases for tax positions related to the current year | 2,539 | 2,661 | 2,068 |
| Gross unrecognized tax benefits at the end of the year | $ 9,540 | $ 7,214 | $ 4,513 |