Amounts Recognized on Consolidated Balance Sheets (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Accrued benefit cost (included in accrued liabilities)	$ (372.3)	$ (347.8)
Pension liabilities	(1,150.5)	(1,076.3)
Postretirement benefits	(241.7)	(227.3)
Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Prepaid pension cost (included in other noncurrent assets)	4.4	9.5
Accrued benefit cost (included in accrued liabilities)	(7.4)	(7.2)
Pension liabilities	(1,150.5)	(1,076.3)
Net liabilities recognized in the consolidated balance sheets	(1,153.5)	(1,074.0)
Other Postretirement Benefit Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Accrued benefit cost (included in accrued liabilities)	(1.4)	(1.1)
Postretirement benefits	(241.7)	(227.3)
Net liabilities recognized in the consolidated balance sheets	$ (243.1)	$ (228.4)