Accounts Receivable, net	9 Months Ended
Jun. 30, 2025
Receivables [Abstract]
Accounts Receivable, net	4. Accounts Receivable, net Accounts receivable of $396.2 and $415.2, is net of an allowance for doubtful accounts of $11.0 and $10.0 and includes amounts of retention on incomplete projects to be completed within one year of $58.3 and $65.7 as of June 30, 2025 and September 30, 2024, respectively.

The entire disclosure for accounts receivable, contract receivable, receivable held-for-sale, and nontrade receivable.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/310/tableOfContent

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/326/tableOfContent

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