Accumulated Other Comprehensive Loss (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012
Accumulated Other Comprehensive Income [Line Items]
Balance at December 31, 2011	$ (3,700.9)
Accumulated other comprehensive loss, Change during period	84.8
Balance at Sept. 30, 2012	(3,616.1)
Translation Adjustments, Balance at December 31, 2011	(649.1)
Translation Adjustments, Change during period	17.0
Translation Adjustments, Balance at September 30, 2012	(632.1)
Postretirement Plans, Balance at December 31, 2011	(3,051.8)
Postretirement plans, Change during period	67.8
Postretirement Plans, Balance at September 30, 2012	$ (2,984.0)