Revenue Recognition (Tables)

6 Months Ended

Mar. 31, 2022

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, 2022 and 2021 (dollars in thousands):

	Three Months Ended March 31,				Six Months Ended March 31,
	2022		2021		2022		2021
Revenues:
United States	$	21,955	$	36,781	$	57,084	$	68,875
Other Americas		35		25		37		68
Germany		23,131		24,667		42,640		56,711
Other Europe, Middle East and Africa		2,567		13,196		6,530		16,665
Japan		25,413		13,779		51,489		26,452
Other Asia-Pacific		13,179		10,214		22,926		23,534
Total net revenues	$	86,280	$	98,662	$	180,706	$	192,305

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, 2021	$	59,143
Revenues recognized but not billed		63,284
Amounts reclassified to accounts receivable, net		(30,844	)
Foreign exchange impact on ending balance		(5,942	)
Balance as of March 31, 2022	$	85,641

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

	Deferred revenue
Balance as of September 30, 2021	$	276,737
Amounts billed but not recognized		50,996
Revenue recognized		(62,557	)
Foreign exchange impact on ending balance		(3,458	)
Balance as of March 31, 2022	$	261,718

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, 2022 (dollars in thousands):

	Within One Year		Two to Five Years		Greater than Five Years		Total
Total revenue	$	144,805	$	156,100	$	22,954	$	323,859