Label	Element	Value
Spire Alabama Inc [Member]
Dividends, Common Stock, Cash	us-gaap_DividendsCommonStockCash	$ 31,500,000
Retained Earnings [Member]
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	0
Retained Earnings [Member] | Spire Alabama Inc [Member]
Dividends, Common Stock, Cash	us-gaap_DividendsCommonStockCash	$ 31,500,000