Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$ 1,395
Balance at Beginning of Period	29,614
Charged to Costs and Expenses, net of Recoveries	1,009	$ (380)	$ 763
Balance at End of Period	1,453	1,395
Balance at End of Period	30,551	29,614
Inventory Obsolescence Reserve
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	29,614	9,674	6,675
Charged to Costs and Expenses	4,353	21,472	11,212
(Deductions) and Additions	(3,416)	(1,532)	(8,213)
Balance at End of Period	30,551	29,614	9,674
Allowance for Doubtful Accounts on Accounts and Financing Receivables
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	2,415	2,949	2,516
Charged to Costs and Expenses, net of Recoveries	1,009	(380)	763
(Deductions) and Additions	(122)	(154)	(330)
Balance at End of Period	$ 3,302	$ 2,415	$ 2,949