Schedule of Valuation and Qualifying Accounts - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Allowance for doubtful accounts [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$ 10	$ 42	$ 26
Additions Charged (Credited) to Expenses	9		24
Deductions From Reserves		32	8
Balance at End of Period	$ 19	$ 10	42
Restructuring accrual [Member]
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period			416
Deductions From Reserves			$ 416