Segment Information, Geographic Regions, and Major Customers - Revenue by Ship-to Destination (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Total revenue	$ 248,359	$ 245,575	$ 724,097	$ 725,358
Americas [Member]
Segment Reporting Information [Line Items]
Total revenue	129,488	128,252	353,397	363,977
Europe, Middle East, and Africa ("EMEA") [Member]
Segment Reporting Information [Line Items]
Total revenue	85,089	85,009	274,635	264,469
Asia Pacific ("APAC") [Member]
Segment Reporting Information [Line Items]
Total revenue	$ 33,782	$ 32,314	$ 96,065	$ 96,912