Revenue - Deferred revenue (Details) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
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| Revenue | ||
| Remaining performance obligation | $ 2,100 | |
| Change in contract with customer, liability | ||
| Deferred revenue at beginning of the period | $ 30,090 | |
| Amounts invoiced in the period | 3,217 | 30,077 |
| Revenue in the period | (1,122) | (59,505) |
| Changes in variable consideration | (10,396) | |
| Changes in the measure of progress | 5,027 | |
| Foreign exchange arising on consolidation | 33 | $ 4,707 |
| Deferred revenue at end of the period | $ 2,128 | |
| X | ||||||||||
- Definition Amount of increase (decrease) in revenue recognized for cumulative catch-up adjustment from amounts invoiced in the period No definition available.
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- Definition Amount of increase (decrease) in revenue recognized for cumulative catch-up adjustment from foreign exchange on consolidation. No definition available.
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- References No definition available.
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- Definition Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of increase (decrease) in revenue recognized for cumulative catch-up adjustment from change in estimate of transaction price which (increases) decreases obligation to transfer good or service to customer for which consideration from customer has been received or is due. Includes, but is not limited to, change in assessment of whether estimate of variable consideration is constrained. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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| X | ||||||||||
- Definition Amount of increase (decrease) in revenue recognized for cumulative catch-up adjustment from change in measure of progress which (increases) decreases obligation to transfer good or service to customer for which consideration from customer has been received or is due. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- References No definition available.
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- Definition Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of transaction price allocated to performance obligation that has not been recognized as revenue. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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