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Fair Value of Derivative and Other Financial Instruments - Defined Benefit Plans Disclosure (Details) - USD ($) $ in Thousands | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
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Public Service Company of New Mexico | Pension Plan |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | $ 410,463 | $ 576,707 | $ 587,530
Public Service Company of New Mexico | Other Postretirement Benefits |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 70,301 | 95,805 | 93,402
Public Service Company of New Mexico | Fair Value, Inputs, Level 1, 2 and 3 | Pension Plan | Participation in PNMR Master Trust Investments: | Fair Value Measurement [Domain] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 342,183 | 527,873 |
Public Service Company of New Mexico | Fair Value, Inputs, Level 1, 2 and 3 | Pension Plan | Participation in PNMR Master Trust Investments: |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 409,970 | 577,305 |
Public Service Company of New Mexico | Fair Value, Inputs, Level 1, 2 and 3 | Pension Plan | Participation in PNMR Master Trust Investments: | Estimate of Fair Value Measurement |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 67,787 | 49,432 |
Public Service Company of New Mexico | Fair Value, Inputs, Level 1, 2 and 3 | Other Postretirement Benefits |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 70,704 | 96,127 |
Public Service Company of New Mexico | Fair Value, Inputs, Level 1, 2 and 3 | Other Postretirement Benefits | Cash and cash equivalents |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 1,703 | 1,578 |
Public Service Company of New Mexico | Fair Value, Inputs, Level 1, 2 and 3 | Other Postretirement Benefits | Mutual funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 69,001 | 94,549 |
Public Service Company of New Mexico | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Plan | Participation in PNMR Master Trust Investments: |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 143,911 | 235,605 |
Public Service Company of New Mexico | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Postretirement Benefits |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 43,771 | 59,961 |
Public Service Company of New Mexico | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Postretirement Benefits | Cash and cash equivalents |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 1,703 | 1,578 |
Public Service Company of New Mexico | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Postretirement Benefits | Mutual funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 42,068 | 58,383 |
Public Service Company of New Mexico | Significant Other Observable Inputs (Level 2) | Pension Plan | Participation in PNMR Master Trust Investments: |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 198,272 | 292,268 |
Public Service Company of New Mexico | Significant Other Observable Inputs (Level 2) | Other Postretirement Benefits |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 26,933 | 36,166 |
Public Service Company of New Mexico | Significant Other Observable Inputs (Level 2) | Other Postretirement Benefits | Cash and cash equivalents |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 0 | 0 |
Public Service Company of New Mexico | Significant Other Observable Inputs (Level 2) | Other Postretirement Benefits | Mutual funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 26,933 | 36,166 |
Texas-New Mexico Power Company | Pension Plan |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 43,447 | 62,942 | 66,149
Texas-New Mexico Power Company | Other Postretirement Benefits |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 8,718 | 12,593 | $ 12,885
Texas-New Mexico Power Company | Fair Value, Inputs, Level 1, 2 and 3 | Pension Plan | Participation in PNMR Master Trust Investments: | Fair Value Measurement [Domain] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 38,617 | 58,623 |
Texas-New Mexico Power Company | Fair Value, Inputs, Level 1, 2 and 3 | Pension Plan | Participation in PNMR Master Trust Investments: |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 44,050 | 62,585 |
Texas-New Mexico Power Company | Fair Value, Inputs, Level 1, 2 and 3 | Pension Plan | Participation in PNMR Master Trust Investments: | Estimate of Fair Value Measurement |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 5,433 | 3,962 |
Texas-New Mexico Power Company | Fair Value, Inputs, Level 1, 2 and 3 | Other Postretirement Benefits |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 8,722 | 12,630 |
Texas-New Mexico Power Company | Fair Value, Inputs, Level 1, 2 and 3 | Other Postretirement Benefits | Cash and cash equivalents |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 149 | 381 |
Texas-New Mexico Power Company | Fair Value, Inputs, Level 1, 2 and 3 | Other Postretirement Benefits | Mutual funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 8,573 | 12,249 |
Texas-New Mexico Power Company | Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Plan | Participation in PNMR Master Trust Investments: |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 13,556 | 21,390 |
Texas-New Mexico Power Company | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Postretirement Benefits |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 8,167 | 11,956 |
Texas-New Mexico Power Company | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Postretirement Benefits | Cash and cash equivalents |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 149 | 381 |
Texas-New Mexico Power Company | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Postretirement Benefits | Mutual funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 8,018 | 11,575 |
Texas-New Mexico Power Company | Significant Other Observable Inputs (Level 2) | Pension Plan | Participation in PNMR Master Trust Investments: |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 25,061 | 37,233 |
Texas-New Mexico Power Company | Significant Other Observable Inputs (Level 2) | Other Postretirement Benefits |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 555 | 674 |
Texas-New Mexico Power Company | Significant Other Observable Inputs (Level 2) | Other Postretirement Benefits | Cash and cash equivalents |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 0 | 0 |
Texas-New Mexico Power Company | Significant Other Observable Inputs (Level 2) | Other Postretirement Benefits | Mutual funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 555 | 674 |
PNMR |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | $ 454,020 | $ 639,890 |
PNMR | Private equity funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible List] | Fair Value Measured at Net Asset Value Per Share | Fair Value Measured at Net Asset Value Per Share |
PNMR | Hedge funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible List] | Fair Value Measured at Net Asset Value Per Share | Fair Value Measured at Net Asset Value Per Share |
PNMR | Real estate funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible List] | Fair Value Measured at Net Asset Value Per Share | Fair Value Measured at Net Asset Value Per Share |
PNMR | Fair Value, Inputs, Level 1, 2 and 3 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | $ 380,800 | $ 586,496 |
PNMR | Fair Value, Inputs, Level 1, 2 and 3 | Cash and cash equivalents |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 17,106 | 18,924 |
PNMR | Fair Value, Inputs, Level 1, 2 and 3 | Corporate stocks, common |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 53,661 | 92,484 |
PNMR | Fair Value, Inputs, Level 1, 2 and 3 | Corporate stocks, preferred |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 639 | 806 |
PNMR | Fair Value, Inputs, Level 1, 2 and 3 | Mutual funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 135,200 | 222,106 |
PNMR | Fair Value, Inputs, Level 1, 2 and 3 | U.S. government |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 62,637 | 95,429 |
PNMR | Fair Value, Inputs, Level 1, 2 and 3 | International government |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 3,318 | 5,977 |
PNMR | Fair Value, Inputs, Level 1, 2 and 3 | Municipals |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 4,922 | 6,143 |
PNMR | Fair Value, Inputs, Level 1, 2 and 3 | Corporate and other |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 103,317 | 144,627 |
PNMR | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 157,467 | 256,995 |
PNMR | Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash and cash equivalents |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 17,106 | 18,924 |
PNMR | Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate stocks, common |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 53,661 | 92,484 |
PNMR | Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate stocks, preferred |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 639 | 0 |
PNMR | Quoted Prices in Active Markets for Identical Assets (Level 1) | Mutual funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 27,412 | 59,203 |
PNMR | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. government |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 58,649 | 86,384 |
PNMR | Quoted Prices in Active Markets for Identical Assets (Level 1) | International government |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 0 | 0 |
PNMR | Quoted Prices in Active Markets for Identical Assets (Level 1) | Municipals |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 0 | 0 |
PNMR | Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate and other |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 0 | 0 |
PNMR | Significant Other Observable Inputs (Level 2) |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 223,333 | 329,501 |
PNMR | Significant Other Observable Inputs (Level 2) | Cash and cash equivalents |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 0 | 0 |
PNMR | Significant Other Observable Inputs (Level 2) | Corporate stocks, common |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 0 | 0 |
PNMR | Significant Other Observable Inputs (Level 2) | Corporate stocks, preferred |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 0 | 806 |
PNMR | Significant Other Observable Inputs (Level 2) | Mutual funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 107,788 | 162,903 |
PNMR | Significant Other Observable Inputs (Level 2) | U.S. government |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 3,988 | 9,045 |
PNMR | Significant Other Observable Inputs (Level 2) | International government |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 3,318 | 5,977 |
PNMR | Significant Other Observable Inputs (Level 2) | Municipals |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 4,922 | 6,143 |
PNMR | Significant Other Observable Inputs (Level 2) | Corporate and other |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 103,317 | 144,627 |
PNMR | Fair Value Measured at Net Asset Value Per Share | Private equity funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 6,691 | 10,479 |
PNMR | Fair Value Measured at Net Asset Value Per Share | Hedge funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | 33,258 | 8,913 |
PNMR | Fair Value Measured at Net Asset Value Per Share | Real estate funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, plan assets, amount | $ 33,271 | $ 34,002 |

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