Changes in Components of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ (309.7)	$ (316.8)	$ (364.9)	$ (339.5)
Pension and other retirement benefit plans before reclassification - Net of Tax			4.9	3.3
Reclassification adjustment from AOCI, Pension and Other Postretirement Benefit Plans - Net of Tax	1.3		3.9	4.5
Pension and other retirement benefit - Net of Tax	1.3		8.8	7.8
Net unrealized gain (losses) on cash flow - Net of Tax	3.2	3.2	6.2	1.5
Reclassification gain (losses) on cash flow - Net of Tax	(2.6)	(0.9)	(6.8)	(0.6)
Gains/(Losses) on cash flow hedges - Net of Tax	0.6	2.3	(0.6)	0.9
Foreign currency translation adjustments before reclassification - Net of Tax	51.8	(9.4)	114.4	7.2
Available for sale securities before reclassification - Net of Tax	0.5	0.7	1.6	1.9
Amount reclassified from AOCI, Available fo Sale Securities - Net of Tax	(2.2)		(2.2)
Gains on Available for sale securities - Net of Tax		(1.9)
Other comprehensive income/(loss) before reclassifications	54.3
Amounts reclassified from AOCI	(2.4)	0.6	(4.0)	3.9
Total other comprehensive income (loss) - Net of Tax	52.0	(4.9)	122.0	17.8
Ending Balance	(257.8)	(305.7)	(257.8)	(305.7)
Pension and Other Retirement Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(72.0)	(79.4)	(79.5)	(85.7)
Ending Balance	(70.7)	(77.9)	(70.7)	(77.9)
Gains Losses On Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	0.5	(2.5)	1.7	(1.1)
Ending Balance	1.1	(0.2)	1.1	(0.2)
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(241.8)	(239.4)	(290.2)	(256.0)
Ending Balance	(191.0)	(230.2)	(191.0)	(230.2)
Gains on Available for Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	3.6	4.5	3.1	3.3
Ending Balance	2.8	2.6	2.8	2.6
Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Foreign currency translation adjustments before reclassification - Net of Tax	50.8	9.2	99.2	25.8
Foreign currency translation adjustments - Net of Tax	50.8	9.2	99.2	25.8
Available for sale securities before reclassification - Net of Tax	0.3	(1.9)	0.8	(0.7)
Amount reclassified from AOCI, Available fo Sale Securities - Net of Tax	(1.1)		(1.1)
Gains on Available for sale securities - Net of Tax	(0.8)	(1.9)	(0.3)	(0.7)
Other comprehensive income/(loss) before reclassifications		10.5	111.1	29.9
Total other comprehensive income (loss) - Net of Tax	$ 51.9	$ 11.1	$ 107.1	$ 33.8