Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Cash and Cash Equivalents
Minimum period in which customer credit and debit card transactions are settled	1 day
Maximum period in which customer credit and debit card transactions are settled	3 days
Proceeds due from customers of credit and debit card and PayPal transactions	$ 10.6	$ 20.0
Inventory
Average approximate inventory shrinkage, as percentage of consolidated net sales	1.00%
Period of net sales considered for inventory shrinkage	3 years
Goodwill and Intangible Assets with Indefinite Lives
Impairment losses in connection with the goodwill	0	0	0
Impairment of intangible assets with indefinite lives	0	0	0
Revenue Recognition
Sales returns and allowance, average of net sales (as a percent)	2.00%
Period of sales considered for sales returns and allowances	3 years	3 years	3 years
Shipping and Handling
Shipping and handling costs	48.5	41.3	41.2
Advertising Costs
Advertising costs	$ 83.9	$ 79.8	$ 70.9
Intangible assets with definite lives
Estimated useful life	6 years 4 months 24 days
Minimum
Intangible assets with definite lives
Estimated useful life	1 year
Maximum
Intangible assets with definite lives
Estimated useful life	12 years