Components of Income Tax Expense (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Current:
Federal	$ 1.8	$ 0.5	$ 0.8
State	2.3	0.8	1.1
Foreign	28.5	23.0	14.9
Current Income Tax Expense (Benefit), Total	32.6	24.3	16.8
Deferred:
Federal	52.4	39.2	37.5
State	3.9	4.8	5.2
Foreign	6.3	(0.2)	3.1
Total Deferred Income Tax Expense (Benefit), Total	62.6	43.8	45.8
Total income tax expense	$ 95.2	$ 68.1	$ 62.6