Commitments and Contingencies	6 Months Ended
Commitments and Contingencies	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Letters of Credit, Bank Guarantees and Bonds Certain customers require us to post letters of credit, bank guarantees or surety bonds. These security instruments assure that we will perform under the terms of our contract. In the event of default, the counterparty may demand payment from the bank under a letter of credit or bank guarantee, or performance by the surety under a bond. To date, there have been no significant draws or claims related to security instruments for the periods reported. We were contingently liable for letters of credit of $87.8 million as of March 31, 2024. We also had surety bonds totaling $481.9 million that were outstanding, with additional bonding capacity of $718.1 million available, at March 31, 2024. We have strong surety relationships; however, a change in market conditions or the sureties' assessment of our financial position could cause the sureties to require cash collateralization for undischarged liabilities under the bonds. We have an $18.9 million facility agreement (Facility Agreement) between Powell (UK) Limited and a large international bank that provides Powell (UK) Limited the ability to enter into bank guarantees as well as forward exchange contracts and currency options. At March 31, 2024, we had outstanding guarantees totaling $7.4 million, with an additional capacity of $11.5 million available under this Facility Agreement. The Facility Agreement provides for customary events of default and carries cross-default provisions with the U.S. Revolver. If an event of default (as defined in the Facility Agreement) occurs and is continuing, per the terms and subject to the conditions set forth therein, obligations outstanding under the Facility Agreement may be accelerated and declared immediately due and payable. Additionally, we are required to maintain cash collateral for guarantees greater than two years. As of March 31, 2024, we were in compliance with all of the financial covenants of the Facility Agreement. Litigation We are involved in various legal proceedings, claims and other disputes arising from our commercial operations, projects, employees and other matters which, in general, are subject to uncertainties and for which the outcomes are not predictable. Although we can give no assurances about the resolution of pending claims, litigation or other disputes, and the effect such outcomes may have on us, management believes that any ultimate liability resulting from the outcome of such proceedings, to the extent not otherwise provided or covered by insurance, will not have a material adverse effect on our consolidated financial position or results of operations or liquidity. Liquidated Damages Certain of our customer contracts have schedule and performance obligation clauses that, if we fail to meet them, could require us to pay liquidated damages. Each individual contract defines the conditions under which the customer may make a claim against us. As of March 31, 2024, certain contracts had a probable exposure to liquidated damages claims of $1.7 million, which could possibly increase to $2.1 million under certain circumstances. Based on our actual or projected failure to meet these various contractual commitments, $1.0 million has been recorded as a reduction to revenue. We will attempt to obtain change orders, contract extensions or accelerate project completion, which may resolve the potential for any unrecorded liquidated damages claims. Should we fail to achieve relief on some or all of these contractual obligations, we could be required to pay additional liquidated damages, which could negatively impact our future operating results.