Consolidated Revenue Information by Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Revenues	$ 1,062.9	$ 917.1	$ 3,038.6	$ 2,662.1
U S
Segment Reporting Information [Line Items]
Revenues	588.4	545.7	1,734.0	1,571.6
International Regions [Member]
Segment Reporting Information [Line Items]
Revenues	474.5	371.4	1,304.6	1,090.5
International Regions [Member] | Europe Middle East And Africa [Member]
Segment Reporting Information [Line Items]
Revenues	291.0	225.9	779.3	665.4
International Regions [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Revenues	118.6	92.5	336.0	272.0
International Regions [Member] | Americas [Member]
Segment Reporting Information [Line Items]
Revenues	$ 64.9	$ 53.0	$ 189.3	$ 153.1