Property, Plant and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 11,951	$ 9,387	$ 7,872
Cash paid in asset acquisition	$ 14,219	$ 7,244	$ 0