Significant Accounting Policies - Assessment of Revenue under ASC 606 (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Sep. 30, 2019
Accounts Receivable, Net [Roll Forward]
Amounts Invoiced and Not Collected, beginning	$ 9,006
Proceeds from Sale and Collection of Receivables	(4,495)
Amounts Invoiced and Not Collected, ending	4,511
Deferred Cost of Sales [Roll Forward]
Deferred Cost of Sales, beginning	1,261
Deferred Cost of Sales, Cash Collected	(629)
Deferred Cost of Sales, ending	$ 632
Amounts Invoiced and Not Collected, Write-off of Deferred Costs for Customer Contracts where Collection is no Longer Reasonable Assured		$ 10,300