Property and Equipment, Net - Tabular Disclosure (Details) - USD ($) $ in Thousands |
Mar. 31, 2018 |
Dec. 31, 2017 |
|---|---|---|
| Property and equipment, net | ||
| Property and equipment, gross | $ 28,523 | $ 26,672 |
| Less: Accumulated depreciation and amortization | (15,727) | (14,213) |
| Property and equipment, net | 12,796 | 12,459 |
| Computer equipment | ||
| Property and equipment, net | ||
| Property and equipment, gross | 13,120 | 12,349 |
| Computer software | ||
| Property and equipment, net | ||
| Property and equipment, gross | 3,149 | 3,048 |
| Leasehold improvements | ||
| Property and equipment, net | ||
| Property and equipment, gross | 6,417 | 6,327 |
| Furniture and fixtures | ||
| Property and equipment, net | ||
| Property and equipment, gross | 3,093 | 2,870 |
| Office equipment | ||
| Property and equipment, net | ||
| Property and equipment, gross | 104 | 99 |
| Construction in progress | ||
| Property and equipment, net | ||
| Property and equipment, gross | 368 | |
| Internal-use software | ||
| Property and equipment, net | ||
| Property and equipment, gross | $ 2,272 | $ 1,979 |