Reconciliation of Activity Related to Company's Accrued Warranty Expense (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accrued Warranty [Line Items]
Balance at beginning of period	$ 63.2	$ 51.5	$ 38.0
Provision for warranty expense	42.6	37.5	34.5
Settlements of warranty claims	(38.8)	(25.8)	(21.0)
Balance at end of period	$ 67.0	$ 63.2	$ 51.5