Consolidated Revenue Information by Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Revenues	$ 1,126.7	$ 975.2
U S
Segment Reporting Information [Line Items]
Revenues	597.7	577.8
International Regions [Member]
Segment Reporting Information [Line Items]
Revenues	529.0	397.4
International Regions [Member] | Europe Middle East And Africa [Member]
Segment Reporting Information [Line Items]
Revenues	347.3	236.3
International Regions [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Revenues	120.2	99.4
International Regions [Member] | Americas [Member]
Segment Reporting Information [Line Items]
Revenues	$ 61.5	$ 61.7