Organization and Basis of Presentation - Narrative (Details) $ in Thousands |
3 Months Ended | 6 Months Ended | |
|---|---|---|---|
|
Mar. 31, 2021
USD ($)
|
Mar. 31, 2021
USD ($)
segment
|
Sep. 30, 2020
USD ($)
|
|
| Organization, Consolidation and Presentation of Financial Statements [Abstract] | |||
| Goodwill | $ 899,796 | $ 899,796 | $ 593,129 |
| Number of operating segments | segment | 3 | ||
| Intangible assets, net | 240,463 | $ 240,463 | $ 145,893 |
| Billed, billable and unbilled accounts receivable | 760,400 | 760,400 | |
| Bad debt expense | $ 300 | $ 900 |
| X | ||||||||||
- Definition Amount of increase (decrease) in allowance for credit loss on accounts receivable. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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| X | ||||||||||
- Definition Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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| X | ||||||||||
- References No definition available.
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| X | ||||||||||
- Definition The total amount due to the entity within one year of the balance sheet date (or one operating cycle, if longer) from outside sources, including trade accounts receivable, notes and loans receivable, as well as any other types of receivables, net of allowances established for the purpose of reducing such receivables to an amount that approximates their net realizable value. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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