Other Income (Expense), net - Details of Other Expense, Net (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Other Income And Expenses [Abstract]
Interest and dividend income	$ 2.6	$ 3.5	$ 8.1	$ 10.2
Net foreign exchange transaction gains (losses)	1.0	(0.8)	(4.6)	(10.8)
Settlement agreement and related costs	(0.3)	(0.4)	(0.6)	(0.6)
Noncontrolling interests		0.4	0.7	2.0
Other, net	(2.9)	(1.3)	(6.4)	(9.0)
Other income (expense), net	$ 0.4	$ 1.4	$ (2.8)	$ (8.2)