Revenue - Contract Estimates (Details) $ in Millions	12 Months Ended
Sep. 30, 2023 USD ($) project	Sep. 30, 2022 USD ($)
Revenue from Contract with Customer [Abstract]
Change in contract estimates related to projects in progress	$ 13.6	$ 11.3
Projects cancelled \| project	4
Change in contract estimates due to project cancellations	$ 4.3

Amount of increase (decrease) in revenue recognized for cumulative catch-up adjustment from change in measure of progress which increases (decreases) right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-10

Name:	us-gaap_ContractWithCustomerAssetCumulativeCatchUpAdjustmentToRevenueChangeInMeasureOfProgress
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration