Contract Balance - Receivables (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Sep. 30, 2023
Revenue from Contract with Customer [Abstract]
Billed	$ 275,400	$ 234,745
Unbilled	209,909	203,896
Receivables Gross	485,309	438,641
Less: allowance for doubtful accounts	(6,187)	(4,978)
Accounts Receivable, after Allowance for Credit Loss	479,122	433,663
Less: long-term receivables	(41,485)	(45,716)
Accounts receivable, net	$ 437,637	$ 387,947

Receivables, Gross

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Amount, before allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business.

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Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business.

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Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

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Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as noncurrent.

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Amount of allowance for credit loss on accounts receivable.

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Amount received for services rendered and products shipped, but not yet billed, for non-contractual agreements due within one year or the normal operating cycle, if longer.

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