Revenue from contracts with customers - Changes in Deferred Gift Card and Gift Certificate Revenue (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2019 |
Jun. 30, 2018 |
Jun. 30, 2019 |
Jun. 30, 2018 |
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| Revenue recognized during the period related to redemptions | $ 300 | $ 200 | $ 700 | $ 500 |
| Deferred gift card and gift certificate revenue | ||||
| Deferred revenue, as of December 31, 2018 | 491 | |||
| Additions to deferred gift card and gift certificates revenue | 296 | |||
| Revenue recognized during the period related to redemptions | (566) | |||
| Deferred revenue, as of June 30, 2019 | $ 221 | $ 221 | ||
| X | ||||||||||
- Definition Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Amount of increase (decrease) in obligation to transfer good or service to customer for which consideration from customer has been received or is due, from business combination. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Details
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