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v3.19.3.a.u2

Summary of the Business and Significant Accounting Policies - Narrative (Details) | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | ---
Dec. 31, 2019 USD ($) Facility utility MW | Dec. 31, 2018 USD ($) | Dec. 31, 2017 USD ($) | Sep. 29, 2017 | Sep. 22, 2017 | Sep. 05, 2017 MW | Jun. 30, 2017 USD ($)
Accounting Policies Disclosures [Line Items] |  |  |  |  |  |  |
Number of regulated utilities | utility | 2 |  |  |  |  |  |
Payment defaults | $ 0 |  |  |  |  |  |
Other current assets | 44,472,000 | $ 54,808,000 |  |  |  |  |
Allowance for equity funds used during construction | 9,478,000 | 10,404,000 | $ 9,516,000 |  |  |  |
Plant in service | $ 7,918,601,000 | 7,548,581,000 |  |  |  |  |
PNMR |  |  |  |  |  |  |
Accounting Policies Disclosures [Line Items] |  |  |  |  |  |  |
Number of regulated utilities | utility | 2 |  |  |  |  |  |
Public Service Company of New Mexico |  |  |  |  |  |  |
Accounting Policies Disclosures [Line Items] |  |  |  |  |  |  |
Restricted cash deposits |  |  |  |  |  |  | $ 1,000,000.0
Other current assets | $ 36,561,000 | 43,516,000 |  |  |  |  |
Allowance for funds used during construction, capitalized interest | $ 5,000,000.0 | $ 6,100,000 | $ 6,300,000 |  |  |  |
Allowance for funds used during construction, capitalized interest rate | 2.99% | 3.19% | 3.14% |  |  |  |
Allowance for equity funds used during construction | $ 6,656,000 | $ 8,173,000 | $ 8,664,000 |  |  |  |
Allowance for funds used during construction, capitalized cost of equity rate | 3.95% | 4.25% | 4.30% |  |  |  |
Impairment losses on securities held in the NDT | $ 5,700,000 | $ 13,700,000 | $ 7,100,000 |  |  |  |
Plant in service | 5,753,267,000 | 5,623,520,000 |  |  |  |  |
Texas-New Mexico Power Company |  |  |  |  |  |  |
Accounting Policies Disclosures [Line Items] |  |  |  |  |  |  |
Other current assets | 1,280,000 | 1,114,000 |  |  |  |  |
Allowance for funds used during construction, capitalized interest | $ 2,400,000 | $ 2,300,000 | $ 1,200,000 |  |  |  |
Allowance for funds used during construction, capitalized interest rate | 3.23% | 3.32% | 3.17% |  |  |  |
Allowance for equity funds used during construction | $ 2,800,000 | $ 2,200,000 | $ 900,000 |  |  |  |
Allowance for funds used during construction, capitalized cost of equity rate | 3.78% | 3.29% | 2.29% |  |  |  |
Plant in service | $ 1,919,256,000 | $ 1,686,119,000 |  |  |  |  |
PNMR Development |  |  |  |  |  |  |
Accounting Policies Disclosures [Line Items] |  |  |  |  |  |  |
Solar distributed generation (in mw) | MW | 80 |  |  |  |  | 50 |
NMRD |  |  |  |  |  |  |
Accounting Policies Disclosures [Line Items] |  |  |  |  |  |  |
Solar distributed generation (in mw) | MW | 30 |  |  |  |  |  |
Plant in service | $ 12,400,000 |  |  |  |  |  |
Renewable energy capacity under contract | MW | 85.1 |  |  |  |  |  |
Megawatts supplying energy to data center (in mw) | MW | 80 |  |  |  |  |  |
Megawatts supplying energy to cooperative (in mw) | MW | 1.9 |  |  |  |  |  |
Megawatts supplying energy to power city (in mw) | MW | 1.2 |  |  |  |  |  |
NMRD | PNMR Development |  |  |  |  |  |  |
Accounting Policies Disclosures [Line Items] |  |  |  |  |  |  |
Ownership percentage |  |  |  |  | 50.00% |  |
Number of solar facilities | Facility | 3 |  |  |  |  |  |
Solar distributed generation (in mw) | MW | 10 |  |  |  |  |  |
Plant in service | $ 24,800,000 |  |  |  |  |  |
Cash contribution percentage | 50.00% |  |  |  |  |  |
NMRD | AEP OnSite Partners |  |  |  |  |  |  |
Accounting Policies Disclosures [Line Items] |  |  |  |  |  |  |
Ownership percentage |  |  |  | 50.00% |  |  |
NMRD | PNMR Development and AEP OnSite |  |  |  |  |  |  |
Accounting Policies Disclosures [Line Items] |  |  |  |  |  |  |
Contribution to construction activities | $ 38,300,000 | $ 9,000,000.0 | $ 4,100,000 |  |  |  |
NMRD | Central New Mexico Electric Cooperative |  |  |  |  |  |  |
Accounting Policies Disclosures [Line Items] |  |  |  |  |  |  |
Megawatts supplying energy to cooperative (in mw) | MW | 2.0 |  |  |  |  |  |

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