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Major Clients (Details) - Revenue - Customer concentration risk | 12 Months Ended
--- | ---
Sep. 30, 2024 | Sep. 30, 2023 | Sep. 30, 2022
Percentage of total revenue |  |  |
Period for which criteria of threshold percentage for disclosure not met in past | 5 years |  |
Minimum |  |  |
Percentage of total revenue |  |  |
Percentage of revenue accounted for by no other single client (as a percent) | 10.00% |  |
Agencies of U.S. Federal Government |  |  |
Percentage of total revenue |  |  |
Concentration (as a percent) | 7.00% | 5.00% | 6.00%

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- Definition Represents the period for which criteria of threshold percentage for disclosure not met in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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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. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 954 -SubTopic 310 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147478785/954-310-50-2 + Details
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