Accounts Receivable, net	9 Months Ended
Jun. 30, 2023
Receivables [Abstract]
Accounts Receivable, net	4. Accounts Receivable, net Accounts receivable of $445.7 and $397.6, is net of an allowance for doubtful accounts of $5.6 and $4.0 and includes amounts of retention on incomplete projects to be completed within one year of $55.4 and $48.8 at June 30, 2023 and September 30, 2022, 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

Name:	us-gaap_AccountsAndNontradeReceivableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration