Net Commission Earned Under Marketing Agreement (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2012	Apr. 02, 2011	Mar. 31, 2012	Apr. 02, 2011
Long-term Purchase Commitment [Line Items]
Gross commission	$ 33.4	$ 32.9	$ 33.4	$ 32.9
Contribution expenses	(5.0)	(5.0)	(10.0)	(10.0)
Amortization of marketing fee	(0.2)	(0.2)	(0.4)	(0.4)
Net commission expense	28.2	27.7	23.0	22.5
Reimbursements associated with Marketing Agreement	23.3	19.0	41.2	34.2
Total net sales associated with Marketing Agreement	$ 51.5	$ 46.7	$ 64.2	$ 56.7