Revenue Recognition (Tables)

6 Months Ended

Mar. 31, 2021

Revenue From Contract With Customer [Abstract]

Summary of Revenues Classified by Major Geographic Region

Revenues, classified by the major geographic region in which our customers are located, for the three and six months ended March 31, 2021 and 2020 (dollars in thousands):

	Three Months Ended March 31,				Six Months Ended March 31,
	2021		2020		2021		2020
Revenues:
United States	$	36,781	$	36,742	$	68,875	$	71,938
Other Americas		25		-		68		8
Germany		24,667		20,102		56,711		40,319
Other Europe, Middle East and Africa		13,196		8,628		16,665		13,225
Japan		13,779		15,518		26,452		26,929
Other Asia-Pacific		10,214		5,833		23,534		12,109
Total net revenues	$	98,662	$	86,823	$	192,305	$	164,528

Summary of Significant Changes in Contract Assets and Deferred Revenue

The table below shows significant changes in contract assets (dollars in thousands):

	Contract assets
Balance as of September 30, 2020	$	30,277
Revenues recognized but not billed		35,323
Amounts reclassified to accounts receivable, net		(27,842	)
Balance as of March 31, 2021	$	37,758
Less: allowance for credit losses		(489	)
Balance as of March 31, 2021, net	$	37,269

The table below shows significant changes in deferred revenue (dollars in thousands):

	Deferred revenue
Balance as of September 30, 2020	$	324,729
Amounts billed but not recognized		55,547
Revenue recognized		(78,475	)
Balance as of March 31, 2021	$	301,801

Summary of Estimated Revenue Expected to be Recognized in Future Related to Performance Obligations Unsatisfied or Partially Unsatisfied

The following table includes estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied or partially unsatisfied at March 31, 2021 (dollars in thousands):

	Within One Year		Two to Five Years		Greater than Five Years		Total
Total revenue	$	150,356	$	176,161	$	22,300	$	348,817