Consolidated Revenue Information by Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Revenues	$ 928.9	$ 918.1	$ 1,745.0	$ 1,783.7
U S
Segment Reporting Information [Line Items]
Revenues	545.9	545.9	1,025.9	1,045.7
International Regions [Member]
Segment Reporting Information [Line Items]
Revenues	383.0	372.2	719.1	738.0
International Regions [Member] | Europe Middle East And Africa [Member]
Segment Reporting Information [Line Items]
Revenues	229.3	217.4	439.5	445.0
International Regions [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Revenues	97.5	99.2	179.5	185.3
International Regions [Member] | Americas [Member]
Segment Reporting Information [Line Items]
Revenues	$ 56.2	$ 55.6	$ 100.1	$ 107.7