Basis of Presentation and Significant Accounting Policies - Effect of New Accounting Pronouncement (Details) - USD ($) $ in Thousands		6 Months Ended
		Mar. 31, 2019	Mar. 31, 2018	Sep. 30, 2018	Sep. 30, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash used in operating activities		$ (3,067)	$ (17,515)
Effect of Exchange Rate Changes on Cash, Cash Equivalents and Restricted Cash		(903)	1,372
Net Decrease in Cash, Cash Equivalents and Restricted Cash		(4,357)	(15,604)
Cash, Cash Equivalents and Restricted Cash, Beginning of Period	[1]	58,139	60,157	$ 62,496	$ 75,761
Cash, Cash Equivalents and Restricted Cash, End of Period	[1]	$ 58,139	60,157	$ 62,496	75,761
As reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash used in operating activities			(1,805)
Effect of Exchange Rate Changes on Cash, Cash Equivalents and Restricted Cash			640
Net Decrease in Cash, Cash Equivalents and Restricted Cash			(626)
Cash, Cash Equivalents and Restricted Cash, Beginning of Period			50,495		51,121
Cash, Cash Equivalents and Restricted Cash, End of Period			$ 50,495		$ 51,121

[1] Includes Cash, Cash Equivalents and Restricted Cash that are included in Held-For-Sale Assets on the Condensed Consolidated Balance Sheets.