Taxation - Income tax uncertainties (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Unrecognized tax benefits, rollforward
January 1	$ 9,276	$ 10,273	$ 5,689
Changes in tax positions taken during a prior period - increase	1,933		3,870
Changes in tax positions taken during a prior period - decrease		(199)
Impact of change in foreign currency exchange rates - Increase			714
Impact of change in foreign currency exchange rates - Decrease	(500)	(798)
December 31	10,709	9,276	10,273
Unrecognized tax benefits impacting effective tax rate	$ 0	$ 0	$ 0

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Amount of unrecognized tax benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
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- Definition

Amount of decrease in unrecognized tax benefits resulting from foreign currency translation.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

+ References

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Amount of increase in unrecognized tax benefits resulting from foreign currency translation.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

+ References

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