Percentage of total capitalization in the covenant of line of credit facility.

No definition available.

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- Definition

Amount of short-term borrowing used to support lending to utilities.

+ References

No definition available.

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

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- Definition

Face (par) amount of debt instrument at time of issuance.

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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- Definition

Amount of cash outflow for short-term and long-term debt. Excludes payment of lease obligation.

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- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Notes Payable and Credit Agreements - Additional Information (Details) - USD ($) $ in Millions	May 06, 2024	Apr. 05, 2024	Jan. 03, 2024	Sep. 30, 2025	Sep. 30, 2024
Short-Term Debt [Line Items]
Borrowings outstanding				$ 1,317.0	$ 947.0
Commercial Paper [Member] \| Parent Company [Member]
Short-Term Debt [Line Items]
Short term borrowings used to support lending to utilities				741.0
Borrowings outstanding				1,317.0	947.0
Maximum [Member] \| Commercial Paper [Member]
Short-Term Debt [Line Items]
Borrowings outstanding				1,500.0
Spire Missouri [Member] \| Loans Payable [Member]
Short-Term Debt [Line Items]
Debt Instrument face amount			$ 200.0
Repayments of Debt	$ 150.0	$ 50.0
Spire Missouri [Member] \| Loans Payable [Member] \| Secured Overnight Financing Rate (SOFR) [Member]
Short-Term Debt [Line Items]
Debt instrument basis spread on variable rate			0.10%
Spire Missouri [Member] \| Loans Payable [Member] \| Adjusted SOFR [Member[
Short-Term Debt [Line Items]
Debt instrument basis spread on variable rate			0.90%
Revolving Credit Facility [Member]
Short-Term Debt [Line Items]
Line of credit facility maximum borrowing capacity				$ 1,500.0
Line of credit facility covenant percentage of total capitalization				65.00%
Long-term line of credit				$ 0.0	$ 0.0
Revolving Credit Facility [Member] \| Maximum [Member]
Short-Term Debt [Line Items]
Line of credit facility covenant percentage of total capitalization				70.00%
Revolving Credit Facility [Member] \| Spire [Member]
Short-Term Debt [Line Items]
Line of credit facility maximum borrowing capacity				$ 525.0
Revolving Credit Facility [Member] \| Spire Missouri [Member]
Short-Term Debt [Line Items]
Line of credit facility maximum borrowing capacity				700.0
Revolving Credit Facility [Member] \| Spire Alabama Inc [Member]
Short-Term Debt [Line Items]
Line of credit facility maximum borrowing capacity				$ 275.0