XML 52 R32.htm IDEA: XBRL DOCUMENT
v3.25.3

Summary of Significant Accounting Policies (Tables) | 12 Months Ended
--- | ---
Sep. 30, 2025
Accounting Policies [Abstract] |
Summary of Non-Utility Property | Non-utility property is as follows:
|  | 2025 |  |  | 2024 |
Storage |  | $ | 453.8 |  |  | $ | 382.0 |
Pipeline |  |  | 498.3 |  |  |  | 492.4 |
All Other Property* |  |  | 184.5 |  |  |  | 177.7 |
Total property, plant and equipment |  | $ | 1,136.6 |  |  | $ | 1,052.1 |
Accumulated depreciation |  |  | (129.4 | ) |  |  | (96.8 | )
Property, plant and equipment, net |  | $ | 1,007.2 |  |  | $ | 955.3 |
* Primarily consisting of computer software and hardware |  |  |  |  |  |
Schedule of Capital Expenditure Excluded From Statement of Cash Flow |
September 30 |  | 2025 |  |  | 2024 |  |  | 2023 |
Spire |  | $ | 82.5 |  |  | $ | 116.5 |  |  | $ | 104.3 |
Spire Missouri |  |  | 61.8 |  |  |  | 67.4 |  |  |  | 56.5 |
Spire Alabama |  |  | 9.5 |  |  |  | 14.1 |  |  |  | 4.6 |
Schedule of Asset Retirement Obligations | The following table presents a reconciliation of the beginning and ending balances of asset retirement obligations at September 30, as reported in the balance sheets.
|  | Spire |  |  | Spire Missouri |  |  | Spire Alabama |
|  | 2025 |  |  | 2024 |  |  | 2025 |  |  | 2024 |  |  | 2025 |  |  | 2024 |
Asset retirement obligations, beginning of year |  | $ | 579.9 |  |  | $ | 577.4 |  |  | $ | 95.7 |  |  | $ | 111.1 |  |  | $ | 468.6 |  |  | $ | 451.0 |
Liabilities incurred during the period |  |  | 3.1 |  |  |  | 2.5 |  |  |  | 0.4 |  |  |  | 0.4 |  |  |  | 2.2 |  |  |  | 1.4 |
Liabilities settled during the period |  |  | (5.1 | ) |  |  | (6.5 | ) |  |  | (2.8 | ) |  |  | (2.9 | ) |  |  | (0.9 | ) |  |  | (1.3 | )
Accretion |  |  | 25.0 |  |  |  | 24.8 |  |  |  | 3.9 |  |  |  | 4.5 |  |  |  | 20.4 |  |  |  | 19.6 |
Revisions in estimated cash flows |  |  | (19.7 | ) |  |  | (18.3 | ) |  |  | (1.7 | ) |  |  | (17.4 | ) |  |  | (20.3 | ) |  |  | (2.1 | )
Asset retirement obligations, end of year |  | $ | 583.2 |  |  | $ | 579.9 |  |  | $ | 95.5 |  |  | $ | 95.7 |  |  | $ | 470.0 |  |  | $ | 468.6 |
Schedule of Related Party Transactions |
|  | Spire Missouri |  |  | Spire Alabama |
|  | 2025 |  |  | 2024 |  |  | 2023 |  |  | 2025 |  |  | 2024 |  |  | 2023 |
Natural gas purchases from Spire Marketing |  | $ | 23.8 |  |  | $ | 13.9 |  |  | $ | 57.4 |  |  | $ | 13.9 |  |  | $ | 6.7 |  |  | $ | 4.7 |
Natural gas sales to Spire Marketing |  |  | 0.1 |  |  |  | 1.7 |  |  |  | 0.4 |  |  |  | — |  |  |  | — |  |  |  | — |
Transportation services from Spire STL Pipeline LLC |  |  | 32.0 |  |  |  | 32.5 |  |  |  | 32.0 |  |  |  | — |  |  |  | — |  |  |  | — |
Natural gas storage services from Spire Storage Salt Plains LLC |  |  | — |  |  |  | 0.7 |  |  |  | 0.7 |  |  |  | — |  |  |  | — |  |  |  | — |
Transportation services from Spire MoGas Pipeline LLC |  |  | 7.0 |  |  |  | 4.8 |  |  |  | — |  |  |  | — |  |  |  | — |  |  |  | — |
Accounts Receivable, Allowance for Credit Loss |
|  | Spire |  |  | Spire Missouri |  |  | Spire Alabama |
|  | 2025 |  |  | 2024 |  |  | 2023 |  |  | 2025 |  |  | 2024 |  |  | 2023 |  |  | 2025 |  |  | 2024 |  |  | 2023 |
Allowance at beginning of year |  | $ | 31.4 |  |  | $ | 32.5 |  |  | $ | 31.9 |  |  | $ | 24.9 |  |  | $ | 26.2 |  |  | $ | 24.9 |  |  | $ | 5.7 |  |  | $ | 5.7 |  |  | $ | 6.3 |
Provision for expected credit losses |  |  | 19.6 |  |  |  | 23.0 |  |  |  | 16.6 |  |  |  | 14.8 |  |  |  | 19.0 |  |  |  | 13.3 |  |  |  | 4.0 |  |  |  | 3.2 |  |  |  | 2.6 |
Write-offs, net of recoveries |  |  | (22.2 | ) |  |  | (24.1 | ) |  |  | (16.0 | ) |  |  | (16.7 | ) |  |  | (20.3 | ) |  |  | (12.0 | ) |  |  | (4.8 | ) |  |  | (3.2 | ) |  |  | (3.2 | )
Allowance at end of year |  | $ | 28.8 |  |  | $ | 31.4 |  |  | $ | 32.5 |  |  | $ | 23.0 |  |  | $ | 24.9 |  |  | $ | 26.2 |  |  | $ | 4.9 |  |  | $ | 5.7 |  |  | $ | 5.7 |

X
- Definition Tabular disclosure of capital expenditure excluded from statement of cash flow. + References No definition available. + Details
Name: | sr_ScheduleOfCapitalExpenditureExcludedFromStatementOfCashFlowTableTextBlock
Namespace Prefix: | sr_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_AccountingPoliciesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of allowance for credit loss on accounts receivable. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 + Details
Name: | us-gaap_AccountsReceivableAllowanceForCreditLossTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of physical assets used in the normal conduct of business and not intended for resale. Includes, but is not limited to, balances by class of assets, depreciation and depletion expense and method used, including composite depreciation, and accumulated deprecation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 1 -SubTopic 10 -Topic 360 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482099/360-10-50-1 + Details
Name: | us-gaap_PropertyPlantAndEquipmentTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the carrying amount of a liability for asset retirement obligations. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 410 -SubTopic 20 -Name Accounting Standards Codification -Paragraph 1 -Section 50 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481850/410-20-50-1 + Details
Name: | us-gaap_ScheduleOfAssetRetirementObligationsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of related party transactions. Examples of related party transactions include, but are not limited to, transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners and (d) affiliates. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 850 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483326/850-10-50-1 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 850 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483326/850-10-50-1 + Details
Name: | us-gaap_ScheduleOfRelatedPartyTransactionsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration