XML 71 R52.htm IDEA: XBRL DOCUMENT
v3.20.2

Revenue - Schedule of Gross Receipts Taxes (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Sep. 30, 2020 | Sep. 30, 2019 | Sep. 30, 2018
Scheduleof Gross Receipts Taxes [Line Items] |  |  |
Gross receipts taxes recorded in regulated gas distribution operating revenues | $ 91.5 | $ 99.3 | $ 98.4
Spire Missouri |  |  |
Scheduleof Gross Receipts Taxes [Line Items] |  |  |
Gross receipts taxes recorded in regulated gas distribution operating revenues | 63.5 | 71.1 | 68.9
Spire Alabama |  |  |
Scheduleof Gross Receipts Taxes [Line Items] |  |  |
Gross receipts taxes recorded in regulated gas distribution operating revenues | $ 23.3 | $ 23.7 | $ 25.4

X
- Definition Amount of gross receipts taxes associated with natural gas utility service, which are imposed on the Utility and billed to its customers. + References No definition available. + Details
Name: | sr_GrossReceiptsTaxAmountsIncludedOperatingRevenues
Namespace Prefix: | sr_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition [Line Items] for Schedule of Gross Receipts Taxes [Table] + References No definition available. + Details
Name: | sr_ScheduleofGrossReceiptsTaxesLineItems
Namespace Prefix: | sr_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | dei_LegalEntityAxis=sr_SpireMissouriMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=sr_SpireAlabamaIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |