Components of Net Periodic Pension and Postretirement Benefit Expense (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Pension Benefits, Domestic
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 2.9	$ 3.6	$ 5.8	$ 7.3
Expected return on plan assets	(4.1)	(4.3)	(8.2)	(8.7)
Amortization, net	1.4	1.2	2.9	2.4
Net periodic expense	0.2	0.5	0.5	1.0
Pension Benefits, Foreign
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.6	0.6	1.1	1.1
Interest cost	0.4	0.6	0.8	1.2
Expected return on plan assets	(0.3)	(0.4)	(0.6)	(0.7)
Amortization, net	0.3	0.1	0.6	0.2
Net periodic expense	1.0	0.9	1.9	1.8
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.6	0.6	1.1	1.1
Interest cost	3.3	4.2	6.6	8.5
Expected return on plan assets	(4.4)	(4.7)	(8.8)	(9.4)
Amortization, net	1.7	1.3	3.5	2.6
Net periodic expense	$ 1.2	1.4	2.4	2.8
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Interest cost		0.1	0.1	0.2
Amortization, net		(0.2)	$ (0.1)	(0.3)
Net periodic expense		$ (0.1)		$ (0.1)