Revenue recognition - Narrative (Details) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Sep. 30, 2020 |
Sep. 30, 2019 |
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| Disaggregation of Revenue [Line Items] | ||
| Deferred revenue, revenue recognized | $ 54,600 | $ 39,900 |
| Accounts receivable — unbilled | 163,332 | 123,884 |
| Cumulative catch-up adjustment to revenue from change in estimates | (9,200) | (10,900) |
| Unbilled receivables | 12,300 | 11,500 |
| Future Outcomes | Performance-based | Transferred over Time | ||
| Disaggregation of Revenue [Line Items] | ||
| Deferred revenue, revenue recognized | 45,000 | |
| Accounts receivable — unbilled | $ 24,800 | $ 47,000 |
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- Definition Amount of increase (decrease) in revenue recognized for cumulative catch-up adjustment from change in estimate of transaction price which increases (decreases) right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time. Includes, but is not limited to, change in assessment of whether estimate of variable consideration is constrained. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Definition Unbilled amounts due for services rendered or to be rendered, actions taken or to be taken, or a promise to refrain from taking certain actions in accordance with the terms of a legally binding agreement between the entity and, at a minimum, one other party. An example would be amounts associated with contracts or programs where the recognized revenue for performance thereunder exceeds the amounts billed under the terms thereof as of the date of the balance sheet. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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