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v3.19.3.a.u2

Construction Program and Jointly-Owned Electric Generating Plants (Details) $ in Thousands | 12 Months Ended
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Dec. 31, 2019 USD ($) generating_unit | Dec. 31, 2018 USD ($) | Dec. 31, 2017 USD ($)
Jointly Owned Utility Plant Interests [Line Items] |  |  |
Construction expenditures | $ 616,273 | $ 501,213 | $ 500,461
Plant in Service | 7,918,601 | 7,548,581 |
Accumulated depreciation | (2,713,503) | (2,604,177) |
Public Service Company of New Mexico |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |
Construction expenditures | 341,847 | 255,627 | 309,142
Plant in Service | 5,753,267 | 5,623,520 |
Accumulated depreciation | (2,076,291) | (2,006,266) |
Texas-New Mexico Power Company |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |
Construction expenditures | 254,006 | 223,448 | $ 145,495
Plant in Service | 1,919,256 | 1,686,119 |
Accumulated depreciation | (516,795) | $ (487,734) |
Joint Projects | Public Service Company of New Mexico |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |
Construction expenditures | 341,800 |  |
Joint Projects | Texas-New Mexico Power Company |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |
Construction expenditures | 254,000 |  |
Joint Projects | PNMR |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |
Construction expenditures | $ 616,300 |  |
SJGS (Coal) | Unit 4 | Other Unrelated Entities 2 |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |
Jointly owned utility plant, ownership percentage | 12.80% |  |
SJGS (Coal) | Unit 4 | Other Unrelated Entities 3 |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |
Jointly owned utility plant, ownership percentage | 8.475% |  |
SJGS (Coal) | Unit 4 | Other Unrelated Entities 4 |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |
Jointly owned utility plant, ownership percentage | 7.20% |  |
SJGS (Coal) | Unit 4 | Other Unrelated Entities 5 |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |
Jointly owned utility plant, ownership percentage | 7.028% |  |
SJGS (Coal) | Public Service Company of New Mexico |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |
Plant in Service | $ 779,236 |  |
Accumulated depreciation | (435,312) |  |
Construction Work in Progress | $ 486 |  |
Composite Interest | 66.35% |  |
SJGS (Coal) | Public Service Company of New Mexico | Unit 4 |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |
Composite Interest | 77.297% |  |
Palo Verde Nuclear Generating Station | Public Service Company of New Mexico |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |
Plant in Service | $ 819,613 |  |
Accumulated depreciation | (369,431) |  |
Construction Work in Progress | $ 31,275 |  |
Composite Interest | 10.20% |  |
Number of units (in generating units) | generating_unit | 3 |  |
Period of time for the original full power operating licenses | 40 years |  |
Operating lease, option term extensions | 20 years |  |
Four Corners | Public Service Company of New Mexico |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |
Number of units (in generating units) | generating_unit | 2 |  |
Four Corners Units 4 and 5 (Coal) | Public Service Company of New Mexico |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |
Plant in Service | $ 283,939 |  |
Accumulated depreciation | (100,137) |  |
Construction Work in Progress | $ 10,794 |  |
Composite Interest | 13.00% |  |
Luna (Gas) | Public Service Company of New Mexico |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |
Plant in Service | $ 78,258 |  |
Accumulated depreciation | (30,255) |  |
Construction Work in Progress | $ 0 |  |
Composite Interest | 33.33% |  |
SJGS Units 1 and 2 | Other Unrelated Entities 1 |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |
Composite Interest | 50.00% |  |
SJGS Units 1 and 2 | Public Service Company of New Mexico |  |  |
Jointly Owned Utility Plant Interests [Line Items] |  |  |
Composite Interest | 50.00% |  |

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