Other Items - Schedule of Accounts Receivable, Net (Details) - USD ($) $ in Thousands |
Mar. 31, 2026 |
Sep. 30, 2025 |
|---|---|---|
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
| Allowance for credit losses | $ (8,798) | $ (9,772) |
| Accounts receivable, net | 1,114,960 | 898,095 |
| Billed and billable receivables | ||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
| Accounts receivable, gross | 868,089 | 720,495 |
| Unbilled receivables | ||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
| Accounts receivable, gross | $ 255,669 | $ 187,372 |
| X | ||||||||||
- 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. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Amount, before allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition 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. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Amount of allowance for credit loss on accounts receivable, classified as current. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|