Pension and Postretirement Benefit Expense (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0.5	$ 0.5	$ 1.5	$ 1.5
Interest cost	4.2	4.7	12.8	14.1
Expected return on plan assets	(4.4)	(4.3)	(13.2)	(12.8)
Amortization, net	1.9	0.9	5.5	2.5
Net periodic expense	2.2	1.8	6.6	5.3
Curtailments and settlements		1.6		1.6
Total expense	2.2	3.4	6.6	6.9
Pension Benefits, Domestic
Defined Benefit Plan Disclosure [Line Items]
Service cost			0.1	0.1
Interest cost	3.6	4.0	10.9	12.0
Expected return on plan assets	(4.1)	(3.9)	(12.2)	(11.7)
Amortization, net	1.8	0.8	5.3	2.4
Net periodic expense	1.3	0.9	4.1	2.8
Curtailments and settlements		1.6		1.6
Total expense	1.3	2.5	4.1	4.4
Pension Benefits, Foreign
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.5	0.5	1.4	1.4
Interest cost	0.6	0.7	1.9	2.1
Expected return on plan assets	(0.3)	(0.4)	(1.0)	(1.1)
Amortization, net	0.1	0.1	0.2	0.1
Net periodic expense	0.9	0.9	2.5	2.5
Total expense	0.9	0.9	2.5	2.5
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost		0.1		0.3
Interest cost	0.1	0.2	0.3	0.6
Amortization, net	(0.1)	(0.3)	(0.4)	(0.7)
Net periodic expense			(0.1)	0.2
Curtailments and settlements		(7.3)		(7.3)
Total expense		$ (7.3)	$ (0.1)	$ (7.1)