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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Part 2 (Details) $ in Thousands | 1 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | ---
Jul. 31, 2024 USD ($) | Jul. 31, 2023 USD ($) | Aug. 31, 2022 USD ($) | Dec. 31, 2024 USD ($) Installment Refund | Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($) | Dec. 31, 2018 USD ($) | Dec. 31, 2017 | Jun. 12, 2024 USD ($) | Jan. 31, 2019 USD ($)
Reclassification of deferred acquisition costs [Abstract] |  |  |  |  |  |  |  |  |  |
Reclassification of deferred acquisition costs from net utility plant |  |  |  |  |  |  |  |  | $ 3,700 |
Reclassification of deferred acquisition costs from contributions in aid of construction |  |  |  |  |  |  |  |  | $ 100 |
Amortization period of other regulatory expense [Abstract] |  |  |  |  |  |  |  |  |  |
Deferred contract costs and other |  |  |  | 5 years |  |  |  |  |  |
Amortization period |  |  |  | 5 years |  |  |  |  |  |
Deferred costs affiliated interest agreement |  |  |  | 20 years |  |  |  |  |  |
Goodwill |  |  |  | 50 years |  |  |  |  |  |
Unrecovered reserve for depreciation (general plant assets) |  |  |  | 5 years |  |  |  |  |  |
Regulatory assets net of amortization, comprise [Abstract] |  |  |  |  |  |  |  |  |  |
Regulatory assets, net |  |  |  | $ 14,428 | $ 7,289 |  |  |  |  |
Impairment or Disposal of Long-Lived Assets [Abstract] |  |  |  |  |  |  |  |  |  |
Impairment |  |  |  | 0 | 0 | $ 0 |  |  |  |
Goodwill [Abstract] |  |  |  |  |  |  |  |  |  |
Goodwill |  |  |  | 1,939 | 1,939 |  |  |  |  |
Summary of other deferred assets net of amortization [Abstract] |  |  |  |  |  |  |  |  |  |
Investment in Co Bank |  |  |  | 6,425 | 5,882 |  |  |  |  |
Settlement agreement receivable-long term |  |  |  | 0 | 2,496 |  |  |  |  |
Other deferred assets |  |  |  | 100 | 126 |  |  |  |  |
Other deferred assets |  |  |  | 6,525 | $ 8,504 |  |  |  |  |
Regulatory Liabilities [Line Items] |  |  |  |  |  |  |  |  |  |
Litigation settlement amount |  |  |  | 10,000 |  |  |  |  |  |
Litigation settlement amount received | $ 2,500 | $ 2,500 | $ 2,500 |  |  |  |  |  |  |
Litigation settlement, remaining amount |  |  |  | $ 2,500 |  |  |  |  |  |
Number of installments | Installment |  |  |  | 3 |  |  |  |  |  |
Number of refunds | Refund |  |  |  | 3 |  |  |  |  |  |
Federal corporate tax rate |  |  |  | 21.00% | 21.00% | 21.00% |  | 34.00% |  |
Decrease in the net deferred income tax liability |  |  |  |  |  |  | $ (24,300) |  |  |
Net regulatory liability amount |  |  |  |  |  |  | $ 22,800 |  |  |
Regulatory Liabilities |  |  |  | $ 30,267 | $ 25,676 |  |  |  |  |
Minimum [Member] |  |  |  |  |  |  |  |  |  |
Amortization period of other regulatory expense [Abstract] |  |  |  |  |  |  |  |  |  |
Debt related costs |  |  |  | 15 years |  |  |  |  |  |
Deferred acquisition and franchise costs - Maryland |  |  |  | 20 years |  |  |  |  |  |
Maximum [Member] |  |  |  |  |  |  |  |  |  |
Amortization period of other regulatory expense [Abstract] |  |  |  |  |  |  |  |  |  |
Debt related costs |  |  |  | 30 years |  |  |  |  |  |
Deferred acquisition and franchise costs - Maryland |  |  |  | 80 years |  |  |  |  |  |
Delaware [Member] |  |  |  |  |  |  |  |  |  |
Amortization period of other regulatory expense [Abstract] |  |  |  |  |  |  |  |  |  |
Rate proceedings |  |  |  | 3 years |  |  |  |  |  |
Deferred acquisition costs |  |  |  | 20 years |  |  |  |  |  |
Delaware [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |  |
Amortization period of other regulatory expense [Abstract] |  |  |  |  |  |  |  |  |  |
Deferred acquisition adjustments |  |  |  | 36 years |  |  |  |  |  |
Delaware [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |
Amortization period of other regulatory expense [Abstract] |  |  |  |  |  |  |  |  |  |
Deferred acquisition adjustments |  |  |  | 62 years |  |  |  |  |  |
DEPSC [Member] |  |  |  |  |  |  |  |  |  |
Regulatory Liabilities [Line Items] |  |  |  |  |  |  |  |  |  |
Net regulatory liability amount |  |  |  |  |  |  |  |  |  | $ 22,200
Regulatory liabilities, amortization period |  |  |  | 49 years 6 months |  |  |  |  | 6 years |
Gross-up adjustment |  |  |  |  |  |  |  |  | $ 7,600 |
Regulatory Liabilities |  |  |  |  |  |  |  |  | 4,000 |
MDPSC [Member] |  |  |  |  |  |  |  |  |  |
Regulatory Liabilities [Line Items] |  |  |  |  |  |  |  |  |  |
Net regulatory liability amount |  |  |  | $ 600 |  |  |  |  |  |
Artesian Water [Member] |  |  |  |  |  |  |  |  |  |
Contributions in Aid of Construction [Abstract] |  |  |  |  |  |  |  |  |  |
Amount received in grant |  |  |  | 0 | 3,800 |  |  |  |  |
Deferred Contract Costs and Other [Member] |  |  |  |  |  |  |  |  |  |
Regulatory assets net of amortization, comprise [Abstract] |  |  |  |  |  |  |  |  |  |
Regulatory assets, net |  |  |  | $ 161 | 209 |  |  |  |  |
Rate Case Studies [Member] |  |  |  |  |  |  |  |  |  |
Amortization period of other regulatory expense [Abstract] |  |  |  |  |  |  |  |  |  |
Amortization period |  |  |  | 5 years |  |  |  |  |  |
Regulatory assets net of amortization, comprise [Abstract] |  |  |  |  |  |  |  |  |  |
Regulatory assets, net |  |  |  | $ 141 | 166 |  |  |  |  |
Delaware Rate Proceedings [Member] |  |  |  |  |  |  |  |  |  |
Regulatory assets net of amortization, comprise [Abstract] |  |  |  |  |  |  |  |  |  |
Regulatory assets, net |  |  |  | 474 | 355 |  |  |  |  |
Deferred Income Taxes [Member] |  |  |  |  |  |  |  |  |  |
Regulatory assets net of amortization, comprise [Abstract] |  |  |  |  |  |  |  |  |  |
Regulatory assets, net |  |  |  | 423 | 444 |  |  |  |  |
Debt Related Costs [Member] |  |  |  |  |  |  |  |  |  |
Regulatory assets net of amortization, comprise [Abstract] |  |  |  |  |  |  |  |  |  |
Regulatory assets, net |  |  |  | 3,969 | 4,322 |  |  |  |  |
Deferred Costs Affiliated Interest Agreement [Member] |  |  |  |  |  |  |  |  |  |
Regulatory assets net of amortization, comprise [Abstract] |  |  |  |  |  |  |  |  |  |
Regulatory assets, net |  |  |  | 1,054 | 1,110 |  |  |  |  |
Goodwill [Member] |  |  |  |  |  |  |  |  |  |
Regulatory assets net of amortization, comprise [Abstract] |  |  |  |  |  |  |  |  |  |
Regulatory assets, net |  |  |  | 251 | 258 |  |  |  |  |
Deferred Acquisition and Franchise Costs - Maryland [Member] |  |  |  |  |  |  |  |  |  |
Regulatory assets net of amortization, comprise [Abstract] |  |  |  |  |  |  |  |  |  |
Regulatory assets, net |  |  |  | 499 | 425 |  |  |  |  |
Deferred Acquisition Costs - Delaware [Member] |  |  |  |  |  |  |  |  |  |
Regulatory assets net of amortization, comprise [Abstract] |  |  |  |  |  |  |  |  |  |
Regulatory assets, net |  |  |  | 231 | 0 |  |  |  |  |
Deferred Acquisition Adjustments - Delaware [Member] |  |  |  |  |  |  |  |  |  |
Regulatory assets net of amortization, comprise [Abstract] |  |  |  |  |  |  |  |  |  |
Regulatory assets, net |  |  |  | 3,359 | 0 |  |  |  |  |
Unrecovered Reserve for Depreciation [Member] |  |  |  |  |  |  |  |  |  |
Regulatory assets net of amortization, comprise [Abstract] |  |  |  |  |  |  |  |  |  |
Regulatory assets, net |  |  |  | $ 3,866 | $ 0 |  |  |  | $ 4,300 |

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