Associated Costs and Related Restructuring Charges (Detail) (Integration and optimization program [Member], USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2012
Integration and optimization program [Member]
Restructuring Cost and Reserve [Line Items]
Cumulative associated costs		$ 10.3
Restructuring charges		162.9
Total cumulative associated costs and restructuring charges		173.2
Associated costs	2.9	10.3
Restructuring charges	37.5	110.6
Total associated costs and restructuring charges	$ 40.4	$ 120.9