Schedule II - Valuation and Qualifying Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2010
Valuation Account - Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	$ 339		$ 549		$ 624
Increase (Decrease) to costs and expenses	418		(96)		132
Deductions	462	[1]	114	[1]	207	[1]
Balance at end of period	295		339		549
Reserve for Future Returns and Pricing Adjustments [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	1,280		1,106		1,058
Increase (Decrease) to costs and expenses	4,881		5,156		4,916
Deductions	4,799		4,982		4,868
Balance at end of period	$ 1,362		$ 1,280		$ 1,106

[1] Uncollectible accounts charged against allowance, net of recoveries