XML 68 R50.htm IDEA: XBRL DOCUMENT
v3.23.3

Note 5 - Other Investments (Details Textual) - RGC Midstream LLC [Member] - USD ($) $ in Millions | 3 Months Ended |
--- | --- | ---
Sep. 30, 2022 | Mar. 31, 2022 | Sep. 30, 2023
MVP Southgate Investment [Member] |  |  |
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners |  |  | 1.00%
MVP [Member] |  |  |
Equity Method Investment, Ownership Percentage |  |  | 1.00%
Long Term Investment, Other than Temporary Impairment | $ 15.3 | $ 39.8 |

X
- Definition The amount of other than temporary impairment (OTTI) losses on long term investments. + References No definition available. + Details
Name: | rgco_LongTermInvestmentOtherThanTemporaryImpairment
Namespace Prefix: | rgco_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 323 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481687/323-10-50-3 + Details
Name: | us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity. + References No definition available. + Details
Name: | us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

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

X
- Details
Name: | srt_OwnershipAxis=rgco_MVPSouthgateInvestmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=rgco_MVPMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |