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Rate and Regulatory Matters (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Jul. 31, 2019	Mar. 31, 2020	Dec. 31, 2019
Delaware Public Service Commission Member
Regulatory Liabilities [Line Items]
Percentage of consumer price index			3.00%
Maturity date			Dec. 31, 2029
Middlesex [Member] | New Jersey Board Of Public Utilities [Member]
Regulatory Liabilities [Line Items]
Approved increase in annual operating revenues		$ 0.6
Tidewater [Member] | Delaware Public Service Commission Member
Regulatory Liabilities [Line Items]
Approved increase in annual operating revenues			$ 0.5
Twin Lakes [Member] | Pennsylvania Public Utilities Commissio [Member]
Regulatory Liabilities [Line Items]
Approved increase in annual operating revenues	$ 0.2	$ 0.1

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Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
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Amount of public utility's approved rate increase (decrease) by regulatory agency.

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