Revenue Recognition (Disaggregated) (Details) - USD ($) $ in Thousands |
3 Months Ended | |
|---|---|---|
Mar. 31, 2019 |
Mar. 31, 2018 |
|
| Disaggregation of Revenue [Line Items] | ||
| Revenue | $ 60,425 | $ 59,149 |
| United States | ||
| Disaggregation of Revenue [Line Items] | ||
| Revenue | 41,003 | 40,964 |
| Canada | ||
| Disaggregation of Revenue [Line Items] | ||
| Revenue | 5,171 | 5,264 |
| All other international sources | ||
| Disaggregation of Revenue [Line Items] | ||
| Revenue | $ 14,251 | $ 12,921 |
| International revenue (excluding Canada) as a percent of total revenue | 24.00% | 22.00% |