Debt (Detail) In Millions, unless otherwise specified	Sep. 30, 2012 USD ($)	May 24, 2012 JPY (¥)	Dec. 31, 2011 USD ($)	Sep. 30, 2012 Senior Notes [Member] USD ($)	Dec. 31, 2011 Senior Notes [Member] USD ($)	Sep. 30, 2012 Senior Notes due 2014 [Member] USD ($)	Dec. 31, 2011 Senior Notes due 2014 [Member] USD ($)	Sep. 30, 2012 Senior Notes due 2019 [Member] USD ($)	Dec. 31, 2011 Senior Notes due 2019 [Member] USD ($)	Sep. 30, 2012 Senior Notes due 2021 [Member] USD ($)	Dec. 31, 2011 Senior Notes due 2021 [Member] USD ($)	Sep. 30, 2012 Senior Notes due 2039 [Member] USD ($)	Dec. 31, 2011 Senior Notes due 2039 [Member] USD ($)
Debt Instrument [Line Items]
Senior Credit Facility			$ 143.0
Other short-term debt	0.3		0.3
Total short-term debt	0.3		143.3
Senior notes due						250.0	250.0	500.0	500.0	300.0	300.0	500.0	500.0
Term loan	150.3	11,700.0
Debt discount				(1.8)	(1.8)
Adjustment related to interest rate swaps	35.6		27.8
Total long-term debt	$ 1,734.1		$ 1,576.0