Goodwill and intangible assets - Carrying Amount (Details) - USD ($) $ in Thousands |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|---|---|---|---|
| Intangible assets | |||
| Historical Cost | $ 36,424 | $ 28,905 | |
| Accumulated Amortization | (17,272) | (18,642) | |
| Net | 19,152 | 10,263 | $ 13,783 |
| Venue contracts | |||
| Intangible assets | |||
| Historical Cost | 20,530 | 22,061 | |
| Accumulated Amortization | (13,829) | (13,835) | |
| Net | 6,701 | 8,226 | |
| Backlog | |||
| Intangible assets | |||
| Historical Cost | 7,030 | ||
| Accumulated Amortization | (586) | ||
| Net | 6,444 | ||
| Customer and partner relationships | |||
| Intangible assets | |||
| Historical Cost | 3,780 | ||
| Accumulated Amortization | (206) | ||
| Net | 3,574 | ||
| Non-compete agreements, technology and other | |||
| Intangible assets | |||
| Historical Cost | 5,084 | 6,844 | |
| Accumulated Amortization | (2,651) | (4,807) | |
| Net | $ 2,433 | $ 2,037 |