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REGULATORY PROCEEDINGS (Details) - USD ($) |  | 3 Months Ended
--- | --- | ---
Nov. 24, 2015 | Mar. 31, 2018 | Mar. 31, 2017
Other Proceedings [Abstract] |  |  |
Effective Date | 4.71% |  |
Increase Amount Based On Eligible Plant Improvements Since Last Rate Increase | $ 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 |  | $ 748,000 |
Revenue earned in DSIC rate increases |  | $ 0 | $ 756,000

X
- 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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