Internal-Use Software Development Costs (Details) - USD ($) $ in Thousands |
3 Months Ended | ||
|---|---|---|---|
Mar. 31, 2018 |
Mar. 31, 2017 |
Dec. 31, 2017 |
|
| Research and Development [Abstract] | |||
| Internal use software development costs, gross | $ 47,435 | $ 44,626 | |
| Less: Accumulated amortization | (29,371) | (27,017) | |
| Internal use software development costs, net | 18,064 | $ 17,609 | |
| Capitalized software development costs during the period | 3,000 | $ 2,900 | |
| Amortization expense with respect to software development costs during the period | $ 2,600 | $ 2,000 | |