Basis of Presentation (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013
Accounts receivable reserves
Total accounts receivable reserves	$ 115,450	$ 98,848
Allowance for sales returns
Accounts receivable reserves
Total accounts receivable reserves	12,220	13,549
Promotional program incentive allowances
Accounts receivable reserves
Total accounts receivable reserves	99,807	82,827
Allowance for doubtful accounts
Accounts receivable reserves
Total accounts receivable reserves	$ 3,423	$ 2,472