Changes in Components of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Beginning Balance	$ (51.9)	$ (357.3)	$ (172.2)	$ (364.9)
Pension and other retirement benefit plans before reclassification - Net of Tax	1.2	4.9	1.2	4.9
Reclassification adjustment from AOCI, Pension and Other Postretirement Benefit Plans - Net of Tax	0.7	1.1	1.7	2.6
Pension and other retirement benefit - Net of Tax	1.9	6.0	2.9	7.5
Net unrealized gain (losses) on cash flow - Net of Tax	27.4	(13.5)	18.0	(17.3)
Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	(0.1)	(3.3)	(0.2)	(4.2)
Gains/(Losses) on cash flow hedges - Net of Tax	(0.1)	(0.1)	1.3	(1.2)
Foreign currency translation adjustments before reclassification - Net of Tax	(259.5)	50.5	(134.3)	62.6
Available for sale securities before reclassification - Net of Tax		0.6		1.1
Gains on Available for sale securities - Net of Tax			(2.3)
Amounts reclassified from AOCI	0.6	(2.2)	1.5	(1.6)
Total other comprehensive (loss) income - Net of Tax	(257.7)	57.0	(130.1)	70.0
Ending Balance	(304.8)	(309.7)	(304.8)	(309.7)
Parent [Member]
Foreign currency translation adjustments before reclassification - Net of Tax	(254.7)	41.5	(134.5)	48.4
Foreign currency translation adjustments - Net of Tax	(254.7)	41.5	(134.5)	48.4
Available for sale securities before reclassification - Net of Tax		0.2		0.5
Gains on Available for sale securities - Net of Tax		0.2		0.5
Other comprehensive income/(loss) before reclassifications	(253.5)	49.8	(131.8)	56.8
Total other comprehensive (loss) income - Net of Tax	(252.9)	47.6	(132.6)	55.2
Financial Instruments - Overall (ASU 2016-01) [Member]
Available for sale securities before reclassification - Net of Tax			(2.3)
Amount reclassified from AOCI, Available fo Sale Securities - Net of Tax			(2.3)
Other comprehensive income/(loss) before reclassifications			(2.3)
Gains (Losses) on Cash Flow Hedges [Member]
Beginning Balance	2.3	0.6	0.9	1.7
Net unrealized gain (losses) on cash flow - Net of Tax		3.2	1.5	3.0
Ending Balance	2.2	0.5	2.2	0.5
Pension and Other Retirement Benefits [Member]
Beginning Balance	(60.5)	(78.0)	(61.5)	(79.5)
Ending Balance	(58.6)	(72.0)	(58.6)	(72.0)
Foreign Currency Translation Adjustments [Member]
Beginning Balance	6.3	(283.3)	(113.9)	(290.2)
Ending Balance	$ (248.4)	(241.8)	(248.4)	(241.8)
Gains on Available for Sale Securities [Member]
Beginning Balance		3.4	$ 2.3	3.1
Ending Balance		$ 3.6		$ 3.6