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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Utility Plant (Details) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2020 | Dec. 31, 2019
Depreciable plant and equipment |  |
Equipment | $ 3,645,770 | $ 3,235,415
Office buildings and other structures | $ 27,567 | 24,854
Office Buildings and other structures, useful life | 50 years |
Minimum |  |
Depreciable plant and equipment |  |
Equipment, useful life | 5 years |
Transmission and distribution plant, useful life | 40 years |
Maximum |  |
Depreciable plant and equipment |  |
Equipment, useful life | 50 years |
Transmission and distribution plant, useful life | 65 years |
Utility Plant |  |
Depreciable plant and equipment |  |
Equipment | $ 785,578 | 726,475
Office buildings and other structures | 305,791 | 281,462
Transmission and distribution plant | 2,554,401 | 2,227,478
Total | $ 3,645,770 | $ 3,235,415

X
- Definition Period end amount of property, plant and equipment and Office buildings and other structures owned by public utility. + References No definition available. + Details
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X
- Definition Useful life of assets common to business units owned by public utility, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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- Definition Period end book value of equipment owned (but not classified elsewhere) by the public utility. + References No definition available. + Details
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- Definition Useful life of other equipment owned by public utility, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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- Definition Useful life of utility transmission equipment owned by public utility, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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- Details
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