Changes in Components of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Beginning Balance	$ (364.9)	$ (339.5)	$ (235.2)
Pension and other retirement benefit plans before reclassification - Net of Tax	12.6	0.2	11.4
Reclassification adjustment from AOCI, pension and other retirement benefit plans - Net of Tax	5.4	6.0	8.3
Pension and other post retirement benefit - Net of Tax	18.0	6.2	19.7
Net unrealized gain (losses) on cash flow - Net of Tax	5.9	(0.9)	(1.1)
Reclassification gain (losses) on cash flow hedges - Net of Tax	(6.7)	3.7
Gains/(Losses) on cash flow hedges - Net of Tax	(0.8)	2.8	(1.1)
Foreign currency translation adjustments before reclassification - Net of Tax	189.3	(27.6)	(125.2)
Amount reclassified from AOCI, Foreign currency translation adjustment - Net of Tax		(36.6)	(0.1)
Foreign currency translation adjustments - Net of Tax			(125.3)
Available for sale securities before reclassification - Net of Tax	2.0	2.6	3.3
Amount reclassified from AOCI, available for sale securities - Net of Tax	(3.5)		(0.9)
Available for sale securities - Net of Tax	(1.5)	2.6	2.4
Other comprehensive income/(loss) before reclassifications			(111.6)
Amounts reclassified from AOCI	3.1	(26.9)	7.3
Total other comprehensive income (loss) - Net of Tax	205.0	(52.6)	(104.3)
Ending Balance	(172.2)	(364.9)	(339.5)
Pension and Other Postretirement Plans Costs [Member]
Beginning Balance	(79.5)	(85.7)	(105.4)
Ending Balance	(61.5)	(79.5)	(85.7)
Gains/(Losses) on Cash Flow Hedges [Member]
Beginning Balance	1.7	(1.1)
Ending Balance	0.9	1.7	(1.1)
Parent [Member]
Beginning Balance	(364.9)	(339.5)	(235.2)
Foreign currency translation adjustments before reclassification - Net of Tax	176.3	2.4	(125.2)
Amount reclassified from AOCI, Foreign currency translation adjustment - Net of Tax		(36.6)	(0.1)
Foreign currency translation adjustments - Net of Tax	176.3	(34.2)	(125.3)
Available for sale securities before reclassification - Net of Tax	1.0	(0.2)	3.3
Amount reclassified from AOCI, available for sale securities - Net of Tax	(1.8)		(0.9)
Available for sale securities - Net of Tax	(0.8)	(0.2)	2.4
Other comprehensive income/(loss) before reclassifications	195.8	1.5	(111.6)
Amounts reclassified from AOCI	(3.1)	(26.9)	7.3
Total other comprehensive income (loss) - Net of Tax	192.7	(25.4)	(104.3)
Ending Balance	(172.2)	(364.9)	(339.5)
Parent [Member] | Gains/(Losses) on Cash Flow Hedges [Member]
Foreign currency translation adjustments before reclassification - Net of Tax		2.4
Foreign currency translation adjustments - Net of Tax		(34.2)
Available for sale securities before reclassification - Net of Tax		(0.2)
Available for sale securities - Net of Tax		(0.2)
Other comprehensive income/(loss) before reclassifications		1.5
Total other comprehensive income (loss) - Net of Tax		(25.4)
Parent [Member] | Foreign Currency Gain (Loss) [Member]
Beginning Balance	(290.2)	(256.0)	(130.7)
Ending Balance	(113.9)	(290.2)	(256.0)
Parent [Member] | Available for Sale Securities [Member]
Beginning Balance	3.1	3.3	0.9
Ending Balance	$ 2.3	$ 3.1	$ 3.3