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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - CAPITALIZED AND DEFERRED INTEREST (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
AFUDC:
SBC interest rate	2.55%	2.05%	2.54%
Deferred interest	$ 78	$ 54	$ 61
Seven-Year Treasury Rate
AFUDC:
Debt instrument, term	7 years
Basis spread on variable rate	60.00%
Natural Gas Distribution
AFUDC:
Debt	$ 1,311	5,009	2,472
Equity	3,867	4,375	3,825
Total	$ 5,178	$ 9,384	$ 6,297
Weighted average interest rate	6.90%	5.06%	4.63%

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- Definition

Deferred Interest related to specific regulatory filings

+ References

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- Definition

SBC Interest Rate

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- Definition

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

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- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Total increase in earnings in the period representing the cost of equity (based on assumed rate of return) and/or borrowed funds (based on interest rate) used to finance construction of regulated assets, which is expected to be recovered through rate adjustments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 340
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44278-110382

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 360
-Section 25
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6500269&loc=d3e45485-110386

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

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The component of the allowance for funds used during construction during the period based on an assumed rate of return on equity funds used in financing the construction of regulated assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 835
-Section 25
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6501569&loc=d3e55921-110430

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-Name Accounting Standards Codification
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-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6501662&loc=d3e56162-110433

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- Definition

Amount capitalized of allowance for funds used during construction.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 835
-Section 25
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6501569&loc=d3e55921-110430

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- Definition

Effective rate, including composite rate, of cost of financing additions to qualifying regulated assets, commonly called allowance for funds used during construction.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 835
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6501662&loc=d3e56162-110433

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