Description of Business and Summary of Significant Accounting Policies (Disaggregated Revenue) (Details) - USD ($) $ in Thousands |
3 Months Ended | |
|---|---|---|
Mar. 31, 2018 |
Mar. 31, 2017 |
|
| Description Of Business And Summary Of Significant Accounting Policies [Line Items] | ||
| Total revenue | $ 59,149 | $ 50,208 |
| International revenue (excluding Canada) as a percent of total revenue | 22.00% | 21.00% |
| United States | ||
| Description Of Business And Summary Of Significant Accounting Policies [Line Items] | ||
| Total revenue | $ 40,964 | $ 35,172 |
| Canada | ||
| Description Of Business And Summary Of Significant Accounting Policies [Line Items] | ||
| Total revenue | 5,264 | 4,247 |
| All other international sources | ||
| Description Of Business And Summary Of Significant Accounting Policies [Line Items] | ||
| Total revenue | $ 12,921 | $ 10,789 |
| Subscription Service | ||
| Description Of Business And Summary Of Significant Accounting Policies [Line Items] | ||
| Contracted not recognized revenue, recognition period | 1 year | |