Major Clients (Details) - Revenue - Customer Concentration Risk	12 Months Ended
Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Percentage of total revenue
Period for which criteria of threshold percentage for disclosure not met in past	5 years
Agencies of U.S. Federal Government
Percentage of total revenue
Concentration risk (as percent)	7.00%	7.00%	5.00%

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.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 275
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-Name Accounting Standards Codification
-Section 50
-Paragraph 18
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482861/275-10-50-18

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 275
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-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482861/275-10-50-18

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 275
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-Paragraph 20
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482861/275-10-50-20

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 275
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Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 275
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Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 275
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-Name Accounting Standards Codification
-Section 50
-Paragraph 18
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482861/275-10-50-18

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 275
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 275
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 954
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478785/954-310-50-2

+ Details

- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References + Details