Investments in Foreign Joint Venture - Schedule of Financial Information of Foreign Joint Venture (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
BOMAY
Assets:
Total current assets	$ 54,158	$ 50,000	$ 54,158	$ 50,000
Total non-current assets	3,154	3,457	3,154	3,457
Total assets	57,312	53,457	57,312	53,457
Liabilities and equity:
Total liabilities	31,788	25,598	31,788	25,598
Total joint ventures’ equity	25,524	27,859	25,524	27,859
Total liabilities and equity	57,312	53,457	57,312	53,457
Revenue	9,283	6,076	29,592	17,225
Gross Profit	1,918	1,160	5,615	3,805
Earnings	$ 627	245	$ 1,764	709
MIEFE
Assets:
Total current assets		121		121
Total non-current assets		15		15
Total assets		136		136
Liabilities and equity:
Total liabilities		198		198
Total joint ventures’ equity		(62)		(62)
Total liabilities and equity		136		136
Revenue		46		80
Gross Profit		10		22
Earnings		$ 11		$ 51