Uncertain Tax Positions - Additional Information (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($)
Income Tax Contingency [Line Items]
Decrease in unrecognized tax benefit from prior years tax audit	$ 3,003
Foreign tax jurisdictions
Income Tax Contingency [Line Items]
Decrease in unrecognized tax benefit from prior years tax audit	1,800
Accrued interest related to unrecognized tax benefit	$ 130