Taxation - Schedule of Current and Deferred Portions of Income Tax Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Taxation
Current income tax (benefits)/expenses	$ 183	$ 315	$ (471)
Deferred income tax expenses	966	4,361	382
Income tax (benefits)/expenses	$ 1,149	$ 4,676	$ (89)

Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration