Segment and Geographic Information - Geographic Information Regarding Revenues (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Revenues:
Total revenues	$ 436,216	$ 404,189	$ 1,298,207	$ 1,323,690
United States [Member]
Revenues:
Total revenues	263,151	229,174	753,456	728,700
United Kingdom [Member]
Revenues:
Total revenues	97,579	95,964	303,480	323,555
Asia [Member]
Revenues:
Total revenues	37,649	41,419	118,651	137,085
France [Member]
Revenues:
Total revenues	17,164	19,627	65,043	69,208
Other Americas [Member]
Revenues:
Total revenues	10,856	8,034	25,998	29,014
Other Europe/MEA [Member]
Revenues:
Total revenues	$ 9,817	$ 9,971	$ 31,579	$ 36,128