Shareholders' Equity |
9 Months Ended |
|---|---|
Jun. 30, 2025 | |
| Stockholders' Equity Note [Abstract] | |
| Shareholders' Equity | ATM Program Under Spire’s “at-the-market” (ATM) equity distribution agreement and as authorized by its board of directors, the Company may offer and sell, from time to time, shares of its common stock (including shares of common stock that may be sold pursuant to forward sale agreements entered into in connection with the ATM equity distribution agreement). Settled sales under this ATM program are included in “Common stock issued” in the Condensed Consolidated Statements of Shareholders’ Equity. Specifically in the first quarter of fiscal 2024, on December 11, 2023, 1,744,549 shares were settled, generating $112.2 of net proceeds. On January 25, 2024, Spire’s board approved a new authorization for the sale of additional shares with an aggregate amount up to $200.0 through January 2027. In the second and third quarters of fiscal 2024, Spire executed forward sale agreements for a total of 542,515 shares of its common stock, which were settled in December 2024, generating $32.4 of net proceeds. In the fourth quarter of fiscal 2024, Spire executed forward sale agreements for 663,619 shares of its common stock, which were settled in March 2025, generating proceeds of $42.4. As of June 30, 2025, there were no outstanding forward sales agreements. As of June 30, 2025, under the ATM Program, Spire may sell additional shares with an aggregate amount up to $123.6. |