Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Goodwill, impairment charges			$ 0
Impairment of indefinite-lived intangibles					$ 0
Accumulated amortization including foreign subsidiaries	$ 85,302,000		85,302,000		$ 56,782,000
Amortization expense including adjustments from fluctuations in foreign currency exchange rates	$ 9,481,000	$ 9,488,000	$ 28,435,000	$ 28,523,000