Employee Benefit Plans Net Periodic Benefit Cost (Detail) £ in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2013 GBP (£)
Pension Benefits, U.S. Plans
Defined Benefit Plans and Other Postretirement Benefit Plans
Service Cost	$ 3.8	$ 3.7	$ 59.4
Interest Cost	82.2	89.9	86.3
Expected Return on Plan Assets	(108.9)	(117.8)	(105.5)
Amortization of Net Actuarial Loss	11.6	5.2	31.7
Amortization of Prior Service Cost (Credit)	0.0	0.0	(0.1)
Recognized Net Gain (Loss) Due to Curtailments	0.0	0.0	0.7
Pension Settlement Costs	0.0	64.4	0.0
Net Periodic Benefit Cost	(11.3)	45.4	72.5
Pension Benefits, Non U.S. Plans
Defined Benefit Plans and Other Postretirement Benefit Plans
Service Cost	0.0	2.3	4.3
Interest Cost	7.9	9.1	8.6
Expected Return on Plan Assets	(12.4)	(13.7)	(12.5)
Amortization of Net Actuarial Loss	0.3	0.4	1.2
Amortization of Prior Service Cost (Credit)	0.0	0.0	0.0
Recognized Net Gain (Loss) Due to Curtailments	0.0	0.0	(3.7)	£ (2.3)
Pension Settlement Costs	0.0	0.0	0.0
Net Periodic Benefit Cost	(4.2)	(1.9)	(2.1)
Other Postretirement Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans
Service Cost	0.0	0.3	0.7
Interest Cost	7.2	7.9	8.0
Expected Return on Plan Assets	(0.7)	(0.7)	(0.6)
Amortization of Net Actuarial Loss	0.0	0.0	0.0
Amortization of Prior Service Cost (Credit)	(0.3)	(1.7)	(4.9)
Recognized Net Gain (Loss) Due to Curtailments	0.0	0.0	0.0
Pension Settlement Costs	0.0	0.0	0.0
Net Periodic Benefit Cost	$ 6.2	$ 5.8	$ 3.2