Warranty Reserve Included in Accrued Expenses and Other Current Liabilities (Detail) (Warranty Reserves, USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 28, 2012	Jul. 30, 2011	Jul. 28, 2012	Jul. 30, 2011
Warranty Reserves
Deferred Revenue and Warranty Reserve [Line Items]
Warranty reserve, beginning of period	$ 15.1	$ 13.1	$ 15.1	$ 13.0
Warranty expense	4.6	0.8	6.1	2.4
Utilized	(2.1)	(1.2)	(3.6)	(2.7)
Warranty reserve, end of period	$ 17.6	$ 12.7	$ 17.6	$ 12.7