v3.7.0.1

Long-Term Debt (Schedule of Long-Term Debt) (Details) - USD ($)			1 Months Ended	9 Months Ended
	Mar. 27, 2017	Nov. 01, 2016	Dec. 31, 2015	Jun. 30, 2017	Sep. 30, 2016
Debt Instrument [Line Items]
Principal				$ 53,336,626	$ 33,896,200
Unamortized Debt Issuance Costs				252,117	260,149
Notes Payable [Member]
Debt Instrument [Line Items]
Principal				42,820,200	33,896,200
Unamortized Debt Issuance Costs				252,117	260,149
Roanoke Gas Company [Member] | Unsecured Senior Notes [Member] | Unsecured Senior Notes Payable at 4.26%, due on September 18, 2034 [Member]
Debt Instrument [Line Items]
Principal				30,500,000	30,500,000
Unamortized Debt Issuance Costs				$ 166,533	173,773
Stated percentage rate				4.26%
Roanoke Gas Company [Member] | Unsecured Term Notes [Member] | Unsecured Term Notes Payable, at 30-day LIBOR plus 0.90%, due November 1, 2021 [Member]
Debt Instrument [Line Items]
Principal				$ 7,000,000	0
Unamortized Debt Issuance Costs				$ 14,451	0
Roanoke Gas Company [Member] | Unsecured Term Notes [Member] | Unsecured Term Notes Payable, at 30-day LIBOR plus 0.90%, due November 1, 2021 [Member] | 30-day LIBOR [Member]
Debt Instrument [Line Items]
Variable rate basis points (as a percent)		0.90%		0.90%
Roanoke Gas Company [Member] | Line of Credit [Member] | Line of Credit, at 30-day LIBOR plus 1.00%, due March 31, 2019 [Member]
Debt Instrument [Line Items]
Principal				$ 10,516,426	0
Unamortized Debt Issuance Costs				$ 0	0
Roanoke Gas Company [Member] | Line of Credit [Member] | Line of Credit, at 30-day LIBOR plus 1.00%, due March 31, 2019 [Member] | 30-day LIBOR [Member]
Debt Instrument [Line Items]
Variable rate basis points (as a percent)	1.00%			1.00%
RGC Midstream LLC [Member] | Unsecured Term Notes [Member] | Unsecured Term Notes Payable, at 30-day LIBOR plus 1.60%, due December 29, 2020 [Member]
Debt Instrument [Line Items]
Principal				$ 5,320,200	3,396,200
Unamortized Debt Issuance Costs				$ 71,133	$ 86,376
RGC Midstream LLC [Member] | Unsecured Term Notes [Member] | Unsecured Term Notes Payable, at 30-day LIBOR plus 1.60%, due December 29, 2020 [Member] | 30-day LIBOR [Member]
Debt Instrument [Line Items]
Variable rate basis points (as a percent)			1.60%	1.60%

X

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

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- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

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+ References

No definition available.

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- Definition

The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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