Schedule II (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Valuation and Qualifying Accounts Disclosure [Line Items]
Currency translation adjustments	$ 64	$ 77	$ (934)
Allowance for Trade Receivables [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	2,540	3,841	7,078
Additions: Charged to Costs and Expenses	1,063	255	364
Additions: Charged to Other Accounts	449	233	487
Deductions	(276)	(1,789)	(4,088)
Balance at End of Year	3,776	2,540	3,841
Valuation Allowance of Deferred Tax Assets [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	3,317	6,804	9,486
Additions: Charged to Costs and Expenses	77	53	209
Additions: Charged to Other Accounts	0	0	0
Deductions	320	(3,540)	(2,891)
Balance at End of Year	$ 3,714	$ 3,317	$ 6,804