Revenue Recognition (Tables)

12 Months Ended

Sep. 30, 2023

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 fiscal years ended September 30, 2023, 2022 and 2021 (dollars in thousands):

	Year Ended September 30,
	2023		2022		2021
Revenues:
United States	$	87,120	$	100,564	$	135,033
Other Americas		244		99		175
Germany		87,211		74,550		114,936
Other Europe, Middle East and Africa		15,603		15,579		29,964
Japan		40,122		74,480		62,840
Other Asia-Pacific		64,175		62,619		44,234
Total net revenues	$	294,475	$	327,891	$	387,182

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		96,409
Amounts reclassified to accounts receivable, net		(67,765	)
Foreign exchange impact on ending balance		(11,495	)
Balance as of September 30, 2022	$	76,292
Revenues recognized but not billed		43,749
Amounts reclassified to accounts receivable, net		(65,931	)
Foreign exchange impact on ending balance		2,598
Balance as of September 30, 2023	$	56,708

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		96,165
Revenue recognized		(130,770	)
Foreign exchange impact on ending balance		(3,498	)
Balance as of September 30, 2022	$	238,634
Amounts billed but not recognized		79,114
Revenue recognized		(99,888	)
Foreign exchange impact on ending balance		4,739
Balance as of September 30, 2023	$	222,599

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 September 30, 2023 (dollars in thousands):

	Within One Year		Two to Five Years		Greater than Five Years		Total
Total revenue	$	141,425	$	128,833	$	13,282	$	283,540