Schedule of Valuation and Qualifying Accounts - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Allowance for doubtful accounts [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$ 42	$ 26	$ 40
Additions Charged (Credited) to Expenses		24	(11)
Deductions From Reserves	32	8	3
Balance at End of Period	$ 10	42	26
Restructuring accrual [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period		416	192
Additions Charged (Credited) to Expenses			476
Deductions From Reserves		$ 416	252
Balance at End of Period			$ 416