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REGULATORY PROCEEDINGS (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2016
Other Proceedings [Abstract]
Cumulative DSIC Rate	3.63%		3.63%		4.71%
Eligible Plant Improvements - Cumulative Dollars			$ 24,700,000		$ 16,600,000
Delaware [Member]
Rate Proceedings [Abstract]
Percentage of gross water sales			15.00%
Period to complete rate case by law			7 months
Delaware [Member] | Maximum [Member]
Rate Proceedings [Abstract]
Temporary annual rate increase subject to 15% gross water sales limitation			$ 2,500,000
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 held in reserve pending outcome of TCJA impact to customers	$ 800,000		$ 1,548,000
Revenue earned in DSIC rate increases	$ 0	$ 787,000	$ 0	$ 1,543,000

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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

No definition available.

+ 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.

+ References

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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.

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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

Revenue held in reserve for Distribution System Improvement Charge rate increases pending the outcome of TCJA impact to customers.

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No definition available.

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