Segment and Geographic Information - Information Regarding Long-Lived Assets in Geographic Areas (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Long-lived assets:
Total long-lived assets	$ 1,993,421	$ 1,802,853
United States [Member]
Long-lived assets:
Total long-lived assets	1,540,190	1,373,118
United Kingdom [Member]
Long-lived assets:
Total long-lived assets	347,752	352,232
Asia [Member]
Long-lived assets:
Total long-lived assets	46,291	32,603
Other Europe/MEA [Member]
Long-lived assets:
Total long-lived assets	19,905	10,477
France [Member]
Long-lived assets:
Total long-lived assets	10,757	7,373
Other Americas [Member]
Long-lived assets:
Total long-lived assets	$ 28,526	$ 27,050