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v3.21.1

Financing -Schedule of Short-term Borrowings (Details) - USD ($) $ in Millions | 6 Months Ended |  |
--- | --- | --- | ---
Mar. 31, 2021 | Sep. 30, 2020 | Mar. 31, 2020
Spire Alabama | Spire Note |  |  |
Short-term Debt [Line Items] |  |  |
Weighted average borrowings | $ 59.6 |  |
Highest borrowings outstanding | $ 152.2 |  |
Weighted average interest rate | 0.20% |  |
Borrowings outstanding |  | $ 121.3 | $ 33.0
Weighted average interest rate |  | 0.20% | 1.90%
Spire Alabama | Revolving Credit Facility Borrowings |  |  |
Short-term Debt [Line Items] |  |  |
Borrowings outstanding |  |  | $ 50.0
Weighted average interest rate |  |  | 1.90%
Spire Missouri | Term Loan |  |  |
Short-term Debt [Line Items] |  |  |
Weighted average borrowings | $ 11.0 |  |
Highest borrowings outstanding | $ 250.0 |  |
Weighted average interest rate | 0.80% |  |
Borrowings outstanding | $ 250.0 |  |
Weighted average interest rate | 0.80% |  |
Spire Missouri | Spire Note |  |  |
Short-term Debt [Line Items] |  |  |
Weighted average borrowings | $ 360.8 |  |
Lowest borrowings outstanding | 277.2 |  |
Highest borrowings outstanding | $ 441.9 |  |
Weighted average interest rate | 0.30% |  |
Borrowings outstanding | $ 369.4 | $ 301.2 | $ 39.6
Weighted average interest rate | 0.20% | 0.20% | 1.90%
Spire Missouri | Revolving Credit Facility Borrowings |  |  |
Short-term Debt [Line Items] |  |  |
Borrowings outstanding |  |  | $ 185.1
Weighted average interest rate |  |  | 1.80%
Spire |  |  |
Short-term Debt [Line Items] |  |  |
Weighted average borrowings | $ 681.4 |  |
Lowest borrowings outstanding | 455.5 |  |
Highest borrowings outstanding | $ 850.5 |  |
Weighted average interest rate | 0.40% |  |
Borrowings outstanding | $ 653.5 | $ 648.0 | $ 560.6
Weighted average interest rate | 0.40% | 0.60% | 1.90%
Spire | Term Loan |  |  |
Short-term Debt [Line Items] |  |  |
Weighted average borrowings | $ 63.5 |  |
Highest borrowings outstanding | $ 150.0 |  |
Weighted average interest rate | 1.10% |  |
Borrowings outstanding |  | $ 150.0 | $ 150.0
Weighted average interest rate |  | 1.10% | 2.10%
Spire | Commercial Paper Notes |  |  |
Short-term Debt [Line Items] |  |  |
Weighted average borrowings | $ 606.9 |  |
Lowest borrowings outstanding | 403.5 |  |
Highest borrowings outstanding | $ 775.0 |  |
Weighted average interest rate | 0.30% |  |
Borrowings outstanding | $ 403.5 | $ 498.0 | $ 175.5
Weighted average interest rate | 0.20% | 0.20% | 1.80%

X
- Definition Minimum amount borrowed under the credit facility at any time during the period. + References No definition available. + Details
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