Pensions - Summary of Components of Net Postretirement Pensions Expense (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
U.S. Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefits Paid	$ 1.6	$ 1.5
Service cost	0	0
Interest cost	1.9	2.0
Amortization of actuarial loss	1.6	1.2
Expected return on plan assets	(2.5)	(2.3)
Net postretirement pension expense	1.0	0.9
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year	7.8
Non-U.S. Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefits Paid	1.1	0.4
Service cost	0.1	0.1
Interest cost	0.5	0.7
Amortization of actuarial loss	0.2	0.1
Expected return on plan assets	(0.7)	(0.9)
Net postretirement pension expense	0.1	0
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year	$ 1.2