Income Tax (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Summary of Pre-tax income in jurisdictions
Pre-tax income	$ (3,534)	$ 3,228	$ (6,005)	$ 3,598
PRC [Member]
Summary of Pre-tax income in jurisdictions
Pre-tax income	(3,531)	3,228	(6,000)	3,605
Others [Member]
Summary of Pre-tax income in jurisdictions
Pre-tax income	$ (3)		$ (5)	$ (7)