SCHEDULE II-VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Allowance for sales returns
VALUATION AND QUALIFYING ACCOUNTS
Balance at Beginning of Period	$ 763	$ 788	$ 871
Charged to Costs and Expenses	4,033	4,151	4,023
Deductions	4,045	4,176	4,106
Balance at End of Period	751	763	788
Allowance for doubtful accounts
VALUATION AND QUALIFYING ACCOUNTS
Balance at Beginning of Period	471	864	1,017
Charged to Costs and Expenses	45	(250)
Deductions	183	143	153
Balance at End of Period	333	471	864
Allowance for deferred tax assets
VALUATION AND QUALIFYING ACCOUNTS
Balance at Beginning of Period	1,981	1,653	1,056
Charged to Costs and Expenses	(100)	328	597
Balance at End of Period	1,881	1,981	1,653
Allowance for deferred tax assets | Revised
VALUATION AND QUALIFYING ACCOUNTS
Balance at Beginning of Period	$ 1,647	1,406	1,056
Charged to Costs and Expenses		241	350
Balance at End of Period		$ 1,647	$ 1,406