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REGULATORY PROCEEDINGS (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2016
Other Proceedings [Abstract]
Cumulative DSIC Rate			7.41%	3.63%			5.55%	4.71%
Eligible Plant Improvements - Cumulative Dollars			$ 43,100	$ 24,700			$ 30,400	$ 16,600
Delaware [Member]
Rate Proceedings [Abstract]
Percentage of gross water sales					15.00%
Period to complete rate case by law					7 months
Revenue returned to customers as a result of TCJA					$ 3,800
Delaware [Member] | Maximum [Member]
Rate Proceedings [Abstract]
Temporary annual rate increase subject to 15% gross water sales limitation					$ 2,500
Percentage of rate relief allowed should a rate case not complete					15.00%
Other Proceedings [Abstract]
Distribution System Improvement Charge rate increase applied between base rate filings					7.50%
Distribution System Improvement Charge rate increase within a 12-month period					5.00%
Artesian Water [Member]
Other Proceedings [Abstract]
Revenue earned in DSIC rate increases	$ 1,300	$ 700			$ 3,100	$ 2,200

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- Definition

For a first temporary increase in revenue basis, maximum temporary annual rate charge increase subject to specific gross water sales limitation.

+ References

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+ Details

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- Definition

Ceiling percentage of Distribution System Improvement Charge rate subject to amount billed to customers.

+ References

No definition available.

+ Details

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- Definition

Conditional percentage maximum for increasing Distribution System Improvement Charge rate within a 12-month period.

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- Definition

Increase amount based on eligible plant improvements since the last rate increase.

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- Definition

Percentage of Distribution System Improvement Charge rate increase application filed by company to regulatory.

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- Definition

For a first temporary annual rate increase in revenue basis, maximum percentage of gross water sales increase allowed subject to specific dollar amount limitation.

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- Definition

Percentage of relief that utility may put into effect if condition for rate case period completion not fulfilled by law.

+ References

No definition available.

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- Definition

Period within which rate change case is to complete, by law, after which, entire requested rate relief may go into effect.

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- Definition

Revenue earned due to Distribution System Improvement Charge rate increase.

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- Definition

Amount of revenue refunded to customers as a result of TCJA tax benefits during the period.

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