Components of Net Periodic Pension and Postretirement Benefit Expense (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 0.3	$ 0.3	$ 0.3
Prior service credit	(0.1)	(0.3)	(0.3)
Net actuarial gain	$ (0.2)	(0.2)	(0.1)
Net periodic (income) expense		$ (0.2)	$ (0.1)
Discount rate	3.84%	4.70%	3.90%
Pension Benefits, Domestic
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 14.3	$ 14.6	$ 13.3
Expected return on plan assets	(20.1)	(17.5)	(16.9)
Net actuarial gain	5.7	4.9	7.4
Net periodic (income) expense	(0.1)	2.0	3.8
Curtailments and settlements	5.0	5.7
Total expense	$ 4.9	$ 7.7	$ 3.8
Discount rate	3.98%	4.80%	3.95%
Expected return on plan assets	7.40%	7.50%	7.75%
Pension Benefits, Foreign
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2.3	$ 2.1	$ 2.2
Interest cost	1.5	2.4	2.3
Expected return on plan assets	(1.2)	(1.4)	(1.2)
Prior service credit		(0.9)
Net actuarial gain	1.1	0.3	0.4
Net periodic (income) expense	3.7	2.5	3.7
Curtailments and settlements	0.4	0.2	(0.1)
Total expense	$ 4.1	$ 2.7	$ 3.6
Discount rate	2.23%	3.58%	3.34%
Expected return on plan assets	3.80%	4.20%	3.98%
Rate of compensation increase	2.44%	2.50%	2.56%
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2.3	$ 2.1	$ 2.2
Interest cost	15.8	17.0	15.6
Expected return on plan assets	(21.3)	(18.9)	(18.1)
Prior service credit		(0.9)
Net actuarial gain	6.8	5.2	7.8
Net periodic (income) expense	3.6	4.5	7.5
Curtailments and settlements	5.4	5.9	(0.1)
Total expense	$ 9.0	$ 10.4	$ 7.4
Discount rate	3.69%	4.58%	3.85%
Expected return on plan assets	7.05%	7.11%	7.32%
Rate of compensation increase	2.44%	2.50%	2.56%