Changes in Components of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ (357.3)	$ (301.5)	$ (364.9)	$ (339.5)
Pension and other retirement benefit plans before reclassification - Net of Tax	4.9	3.3	4.9	3.3
Reclassification adjustment from AOCI, Pension and Other Postretirement Benefit Plans - Net of Tax	1.1	1.4	2.6	3.0
Pension and other retirement benefit - Net of Tax	6.0	4.7	7.5	6.3
Net unrealized gain (losses) on cash flow - Net of Tax	3.2	(2.9)	3.0	(1.7)
Reclassification gain (losses) on cash flow - Net of Tax	(3.3)	1.7	(4.2)	0.3
Gains/(Losses) on cash flow hedges - Net of Tax	(0.1)	(1.2)	(1.2)	(1.4)
Foreign currency translation adjustments before reclassification - Net of Tax	50.5	(19.4)	62.6	16.6
Available for sale securities before reclassification - Net of Tax	0.6	0.6	1.1	1.2
Other comprehensive income/(loss) before reclassifications	49.8	(18.4)	56.8	19.4
Amounts reclassified from AOCI	(2.2)	3.1	(1.6)	3.3
Total other comprehensive income (loss) - Net of Tax	57.0	(15.3)	70.0	22.7
Ending Balance	(309.7)	(316.8)	(309.7)	(316.8)
Pension and Other Retirement Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(78.0)	(84.1)	(79.5)	(85.7)
Ending Balance	(72.0)	(79.4)	(72.0)	(79.4)
Gains Losses On Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	0.6	(1.3)	1.7	(1.1)
Ending Balance	0.5	(2.5)	0.5	(2.5)
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(283.3)	(220.0)	(290.2)	(256.0)
Ending Balance	(241.8)	(239.4)	(241.8)	(239.4)
Gains on Available for Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	3.4	3.9	3.1	3.3
Ending Balance	3.6	4.5	3.6	4.5
Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Foreign currency translation adjustments before reclassification - Net of Tax	41.5	(19.4)	48.4	16.6
Foreign currency translation adjustments - Net of Tax	41.5	(19.4)	48.4	16.6
Available for sale securities before reclassification - Net of Tax	0.2	0.6	0.5	1.2
Gains on Available for sale securities - Net of Tax	0.2	0.6	0.5	1.2
Other comprehensive income/(loss) before reclassifications			56.8	19.4
Amounts reclassified from AOCI			(1.6)	3.3
Total other comprehensive income (loss) - Net of Tax	$ 47.6	$ (15.3)	$ 55.2	$ 22.7