0001126956 2026-06-30 2026-06-30 0001126956 sr:CommonStockCustomMember 2026-06-30 2026-06-30 0001126956 sr:SixPointThreeSevenFivePercentageJuniorSubordinatedNotesDue2086Member 2026-06-30 2026-06-30 false 0001126956 8-K 2026-06-30 1-16681 Spire Inc. 700 Market Street St. Louis MO 63101 314 342-0500 MO 74-2976504 false false false false Common Stock $1.00 par value SR NYSE 6.375% Junior Subordinated Notes SRJN NYSE false