Segment and Geographic Information - Geographic Information Regarding Revenues (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues:
Total revenues	$ 2,612,623	$ 2,580,439	$ 1,789,579
United States [Member]
Revenues:
Total revenues	1,531,456	1,505,811	1,078,196
United Kingdom [Member]
Revenues:
Total revenues	620,100	634,336	393,259
Asia [Member]
Revenues:
Total revenues	214,133	217,895	154,480
France [Member]
Revenues:
Total revenues	92,154	85,905	81,662
Other Americas [Member]
Revenues:
Total revenues	54,382	54,421	39,589
Other Europe/MEA [Member]
Revenues:
Total revenues	$ 100,398	$ 82,071	$ 42,393