Land Use Rights - Summary of Land Use Rights Recorded at net Carrying Value (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Cost	$ 3,453	$ 48,733
Less: Accumulated amortization	(740)	(3,458)
Total	$ 2,713	$ 45,275