Domestic and Foreign Income from Continuing Operations before Income Taxes (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Schedule of Components of Income Before Income Tax Expense (Benefit) [Line Items]
U.S.	$ 275.5	$ 203.3	$ 166.5
Foreign	132.7	171.9	164.5
Consolidated income from continuing operations before income taxes	$ 408.2	$ 375.2	$ 331.0