Consolidated Revenue Information by Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Revenues	$ 917.1	$ 834.9	$ 2,662.1	$ 2,618.6
U S
Segment Reporting Information [Line Items]
Revenues	545.7	482.1	1,571.6	1,527.8
International Regions [Member]
Segment Reporting Information [Line Items]
Revenues	371.4	352.8	1,090.5	1,090.8
International Regions [Member] | Europe Middle East And Africa [Member]
Segment Reporting Information [Line Items]
Revenues	225.9	215.4	665.4	660.4
International Regions [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Revenues	92.5	85.5	272.0	270.8
International Regions [Member] | Americas [Member]
Segment Reporting Information [Line Items]
Revenues	$ 53.0	$ 51.9	$ 153.1	$ 159.6