Consolidated Revenue Information by Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Segment Reporting Information [Line Items]
Revenues	$ 1,175.1	$ 1,000.5	$ 2,301.8	$ 1,975.7
U S
Segment Reporting Information [Line Items]
Revenues	625.4	567.8	1,223.1	1,145.6
International Regions [Member]
Segment Reporting Information [Line Items]
Revenues	549.7	432.7	1,078.7	830.1
International Regions [Member] | Europe Middle East And Africa [Member]
Segment Reporting Information [Line Items]
Revenues	356.1	252.0	703.4	488.3
International Regions [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Revenues	123.7	118.0	243.9	217.4
International Regions [Member] | Americas [Member]
Segment Reporting Information [Line Items]
Revenues	$ 69.9	$ 62.7	$ 131.4	$ 124.4