Fair Value Measurement - Additional Information (Detail) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Financial assets, fair value	$ 0	$ 0
Financial liabilities, fair value	0	0
Carrying value	171,525,000	97,741,000
DEG Vietnam Loan
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Carrying value	15,000,000	15,000,000
Fair value	14,900,000	15,100,000
DEG China Loan
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Carrying value	2,525,000	3,497,000
Fair value	$ 2,600,000	$ 3,600,000