Revenue by Geographic Area (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 275,585	$ 245,862	$ 792,914	$ 717,837
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	107,130	91,301	309,486	265,945
Japan
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	30,778	31,496	94,572	90,601
Germany
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	25,391	25,399	71,115	73,428
South Korea
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	15,309	13,381	45,677	41,629
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	16,608	11,271	42,942	29,810
France
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	15,099	12,054	42,482	36,106
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	3,864	3,179	10,368	9,855
Other European
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	37,455	33,991	107,019	103,765
Other international
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 23,951	$ 23,790	$ 69,253	$ 66,698