Reconciliation of Gross Amount of Unrecognized Tax Benefits (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Schedule of Unrecognized Tax Benefits [Line Items]
Balance, January 1	$ 43.4	$ 45.0
Additions related to prior year tax positions	8.5	1.7
Reductions related to prior year tax positions	0	(5.3)
Additions for tax positions of the current year	12.2	7.2
Settlements	(2.4)	(2.8)
Lapse of statutes of limitation	(3.7)	(2.4)
Balance, December 31	$ 58.0	$ 43.4