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Fair Value of Derivative and Other Financial Instruments - Defined Benefit Plans Disclosure (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2017 | Dec. 31, 2016
Public Service Company of New Mexico | Pension Plan |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | $ 543,601 | $ 557,923
Fair value of plan assets at end of year | 562,016 | 543,601
Public Service Company of New Mexico | Pension Plan | Participation in PNMR Master Trust Investments: | Fair Value Measurement [Domain] |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 467,965 |
Fair value of plan assets at end of year | 487,498 | 467,965
Public Service Company of New Mexico | Pension Plan | Participation in PNMR Master Trust Investments: |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 543,650 |
Fair value of plan assets at end of year | 562,266 | 543,650
Public Service Company of New Mexico | Pension Plan | Participation in PNMR Master Trust Investments: | Estimate of Fair Value Measurement |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 75,685 |
Fair value of plan assets at end of year | 74,768 | 75,685
Public Service Company of New Mexico | Other Postretirement Benefits |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Total fair value of plan assets owned | 81,177 | 73,829
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 72,694 | 72,952
Fair value of plan assets at end of year | 80,356 | 72,694
Public Service Company of New Mexico | Other Postretirement Benefits | Cash and cash equivalents |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 2,567 |
Fair value of plan assets at end of year | 437 | 2,567
Public Service Company of New Mexico | Other Postretirement Benefits | International funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 9,300 |
Fair value of plan assets at end of year | 10,636 | 9,300
Public Service Company of New Mexico | Other Postretirement Benefits | Domestic value |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 10,260 |
Fair value of plan assets at end of year | 10,816 | 10,260
Public Service Company of New Mexico | Other Postretirement Benefits | Domestic growth |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 6,338 |
Fair value of plan assets at end of year | 6,710 | 6,338
Public Service Company of New Mexico | Other Postretirement Benefits | Other funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 26,405 |
Fair value of plan assets at end of year | 31,660 | 26,405
Public Service Company of New Mexico | Other Postretirement Benefits | Mutual funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 18,959 |
Fair value of plan assets at end of year | 20,918 | 18,959
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, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 129,624 |
Fair value of plan assets at end of year | 140,218 | 129,624
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] |  |
Total fair value of plan assets owned | 38,881 | 38,124
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, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 2,567 |
Fair value of plan assets at end of year | 437 | 2,567
Public Service Company of New Mexico | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Postretirement Benefits | International funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Public Service Company of New Mexico | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Postretirement Benefits | Domestic value |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 10,260 |
Fair value of plan assets at end of year | 10,816 | 10,260
Public Service Company of New Mexico | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Postretirement Benefits | Domestic growth |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 6,338 |
Fair value of plan assets at end of year | 6,710 | 6,338
Public Service Company of New Mexico | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Postretirement Benefits | Other funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Public Service Company of New Mexico | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Postretirement Benefits | Mutual funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 18,959 |
Fair value of plan assets at end of year | 20,918 | 18,959
Public Service Company of New Mexico | Significant Other Observable Inputs (Level 2) | Pension Plan | Participation in PNMR Master Trust Investments: |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 337,989 |
Fair value of plan assets at end of year | 347,089 | 337,989
Public Service Company of New Mexico | Significant Other Observable Inputs (Level 2) | Other Postretirement Benefits |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Total fair value of plan assets owned | 42,296 | 35,705
Public Service Company of New Mexico | Significant Other Observable Inputs (Level 2) | Other Postretirement Benefits | Cash and cash equivalents |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Public Service Company of New Mexico | Significant Other Observable Inputs (Level 2) | Other Postretirement Benefits | International funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 9,300 |
Fair value of plan assets at end of year | 10,636 | 9,300
Public Service Company of New Mexico | Significant Other Observable Inputs (Level 2) | Other Postretirement Benefits | Domestic value |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Public Service Company of New Mexico | Significant Other Observable Inputs (Level 2) | Other Postretirement Benefits | Domestic growth |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Public Service Company of New Mexico | Significant Other Observable Inputs (Level 2) | Other Postretirement Benefits | Other funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 26,405 |
Fair value of plan assets at end of year | 31,660 | 26,405
Public Service Company of New Mexico | Significant Other Observable Inputs (Level 2) | Other Postretirement Benefits | Mutual funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Public Service Company of New Mexico | Significant Unobservable Inputs (Level 3) | Corporate |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year |  | 719
Actual return on assets sold during the period | 1 | 1
Actual return on assets still held at period end | (7) | 19
Purchases | 92 | 0
Sales | (247) | (387)
Public Service Company of New Mexico | Significant Unobservable Inputs (Level 3) | Pension Plan | Participation in PNMR Master Trust Investments: |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 352 |
Fair value of plan assets at end of year | 191 | 352
Public Service Company of New Mexico | Significant Unobservable Inputs (Level 3) | Other Postretirement Benefits |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Total fair value of plan assets owned | 0 | 0
Public Service Company of New Mexico | Significant Unobservable Inputs (Level 3) | Other Postretirement Benefits | Cash and cash equivalents |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Public Service Company of New Mexico | Significant Unobservable Inputs (Level 3) | Other Postretirement Benefits | International funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Public Service Company of New Mexico | Significant Unobservable Inputs (Level 3) | Other Postretirement Benefits | Domestic value |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Public Service Company of New Mexico | Significant Unobservable Inputs (Level 3) | Other Postretirement Benefits | Domestic growth |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Public Service Company of New Mexico | Significant Unobservable Inputs (Level 3) | Other Postretirement Benefits | Other funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Public Service Company of New Mexico | Significant Unobservable Inputs (Level 3) | Other Postretirement Benefits | Mutual funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Texas-New Mexico Power Company | Pension Plan |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 60,624 | 62,082
Fair value of plan assets at end of year | 63,499 | 60,624
Texas-New Mexico Power Company | Pension Plan | Participation in PNMR Master Trust Investments: | Fair Value Measurement [Domain] |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 50,901 |
Fair value of plan assets at end of year | 53,273 | 50,901
Texas-New Mexico Power Company | Pension Plan | Participation in PNMR Master Trust Investments: |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 60,630 |
Fair value of plan assets at end of year | 63,533 | 60,630
Texas-New Mexico Power Company | Pension Plan | Participation in PNMR Master Trust Investments: | Estimate of Fair Value Measurement |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 9,729 |
Fair value of plan assets at end of year | 10,260 | 9,729
Texas-New Mexico Power Company | Other Postretirement Benefits |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Total fair value of plan assets owned | 10,145 | 8,778
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 8,544 | 9,111
Fair value of plan assets at end of year | 10,002 | 8,544
Texas-New Mexico Power Company | Other Postretirement Benefits | Cash and cash equivalents |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 308 |
Fair value of plan assets at end of year | 149 | 308
Texas-New Mexico Power Company | Other Postretirement Benefits | International funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 1,279 |
Fair value of plan assets at end of year | 1,597 | 1,279
Texas-New Mexico Power Company | Other Postretirement Benefits | Domestic value |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 449 |
Fair value of plan assets at end of year | 293 | 449
Texas-New Mexico Power Company | Other Postretirement Benefits | Domestic growth |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 1,089 |
Fair value of plan assets at end of year | 1,410 | 1,089
Texas-New Mexico Power Company | Other Postretirement Benefits | Other funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 3,060 |
Fair value of plan assets at end of year | 4,011 | 3,060
Texas-New Mexico Power Company | Other Postretirement Benefits | Mutual funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 2,593 |
Fair value of plan assets at end of year | 2,685 | 2,593
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, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 14,447 |
Fair value of plan assets at end of year | 15,244 | 14,447
Texas-New Mexico Power Company | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Postretirement Benefits |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Total fair value of plan assets owned | 4,537 | 4,439
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, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 308 |
Fair value of plan assets at end of year | 149 | 308
Texas-New Mexico Power Company | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Postretirement Benefits | International funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Texas-New Mexico Power Company | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Postretirement Benefits | Domestic value |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 449 |
Fair value of plan assets at end of year | 293 | 449
Texas-New Mexico Power Company | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Postretirement Benefits | Domestic growth |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 1,089 |
Fair value of plan assets at end of year | 1,410 | 1,089
Texas-New Mexico Power Company | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Postretirement Benefits | Other funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Texas-New Mexico Power Company | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Postretirement Benefits | Mutual funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 2,593 |
Fair value of plan assets at end of year | 2,685 | 2,593
Texas-New Mexico Power Company | Significant Other Observable Inputs (Level 2) | Pension Plan | Participation in PNMR Master Trust Investments: |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 36,416 |
Fair value of plan assets at end of year | 38,008 | 36,416
Texas-New Mexico Power Company | Significant Other Observable Inputs (Level 2) | Other Postretirement Benefits |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Total fair value of plan assets owned | 5,608 | 4,339
Texas-New Mexico Power Company | Significant Other Observable Inputs (Level 2) | Other Postretirement Benefits | Cash and cash equivalents |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Texas-New Mexico Power Company | Significant Other Observable Inputs (Level 2) | Other Postretirement Benefits | International funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 1,279 |
Fair value of plan assets at end of year | 1,597 | 1,279
Texas-New Mexico Power Company | Significant Other Observable Inputs (Level 2) | Other Postretirement Benefits | Domestic value |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Texas-New Mexico Power Company | Significant Other Observable Inputs (Level 2) | Other Postretirement Benefits | Domestic growth |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Texas-New Mexico Power Company | Significant Other Observable Inputs (Level 2) | Other Postretirement Benefits | Other funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 3,060 |
Fair value of plan assets at end of year | 4,011 | 3,060
Texas-New Mexico Power Company | Significant Other Observable Inputs (Level 2) | Other Postretirement Benefits | Mutual funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Texas-New Mexico Power Company | Significant Unobservable Inputs (Level 3) | Corporate |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year |  | 78
Actual return on assets sold during the period | 0 | 0
Actual return on assets still held at period end | (1) | 2
Purchases | 10 | 0
Sales | (26) | (42)
Texas-New Mexico Power Company | Significant Unobservable Inputs (Level 3) | Pension Plan | Participation in PNMR Master Trust Investments: |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 38 |
Fair value of plan assets at end of year | 21 | 38
Texas-New Mexico Power Company | Significant Unobservable Inputs (Level 3) | Other Postretirement Benefits |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Total fair value of plan assets owned | 0 | 0
Texas-New Mexico Power Company | Significant Unobservable Inputs (Level 3) | Other Postretirement Benefits | Cash and cash equivalents |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Texas-New Mexico Power Company | Significant Unobservable Inputs (Level 3) | Other Postretirement Benefits | International funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Texas-New Mexico Power Company | Significant Unobservable Inputs (Level 3) | Other Postretirement Benefits | Domestic value |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Texas-New Mexico Power Company | Significant Unobservable Inputs (Level 3) | Other Postretirement Benefits | Domestic growth |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Texas-New Mexico Power Company | Significant Unobservable Inputs (Level 3) | Other Postretirement Benefits | Other funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
Texas-New Mexico Power Company | Significant Unobservable Inputs (Level 3) | Other Postretirement Benefits | Mutual funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
PNMR | Fair Value Measurement [Domain] |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 518,866 |
Fair value of plan assets at end of year | 540,771 | 518,866
PNMR |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 604,280 |
Fair value of plan assets at end of year | 625,799 | 604,280
PNMR | Cash and cash equivalents |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 20,503 |
Fair value of plan assets at end of year | 7,697 | 20,503
PNMR | International funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 38,401 |
Fair value of plan assets at end of year | 42,048 | 38,401
PNMR | Domestic value |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 36,036 |
Fair value of plan assets at end of year | 37,026 | 36,036
PNMR | Domestic growth |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 18,484 |
Fair value of plan assets at end of year | 19,136 | 18,484
PNMR | Other funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 27,532 |
Fair value of plan assets at end of year | 25,099 | 27,532
PNMR | Corporate |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 205,419 |
Fair value of plan assets at end of year | 215,535 | 205,419
PNMR | U.S. Government |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 94,359 |
Fair value of plan assets at end of year | 117,572 | 94,359
PNMR | Municipals |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 13,970 |
Fair value of plan assets at end of year | 11,438 | 13,970
PNMR | Other funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 64,162 |
Fair value of plan assets at end of year | 65,220 | 64,162
PNMR | Private equity funds | Estimate of Fair Value Measurement |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 27,060 |
Fair value of plan assets at end of year | 22,281 | 27,060
PNMR | Hedge funds | Estimate of Fair Value Measurement |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 42,070 |
Fair value of plan assets at end of year | 45,615 | 42,070
PNMR | Real estate funds | Estimate of Fair Value Measurement |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 16,284 |
Fair value of plan assets at end of year | 17,132 | 16,284
PNMR | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 144,071 |
Fair value of plan assets at end of year | 155,462 | 144,071
PNMR | Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash and cash equivalents |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 20,503 |
Fair value of plan assets at end of year | 7,697 | 20,503
PNMR | Quoted Prices in Active Markets for Identical Assets (Level 1) | International funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
PNMR | Quoted Prices in Active Markets for Identical Assets (Level 1) | Domestic value |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 36,036 |
Fair value of plan assets at end of year | 37,026 | 36,036
PNMR | Quoted Prices in Active Markets for Identical Assets (Level 1) | Domestic growth |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 18,484 |
Fair value of plan assets at end of year | 19,136 | 18,484
PNMR | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
PNMR | Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
PNMR | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Government |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 69,048 |
Fair value of plan assets at end of year | 91,603 | 69,048
PNMR | Quoted Prices in Active Markets for Identical Assets (Level 1) | Municipals |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
PNMR | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
PNMR | Significant Other Observable Inputs (Level 2) |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 374,405 |
Fair value of plan assets at end of year | 385,097 | 374,405
PNMR | Significant Other Observable Inputs (Level 2) | Cash and cash equivalents |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
PNMR | Significant Other Observable Inputs (Level 2) | International funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 38,401 |
Fair value of plan assets at end of year | 42,048 | 38,401
PNMR | Significant Other Observable Inputs (Level 2) | Domestic value |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
PNMR | Significant Other Observable Inputs (Level 2) | Domestic growth |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
PNMR | Significant Other Observable Inputs (Level 2) | Other funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 27,532 |
Fair value of plan assets at end of year | 25,099 | 27,532
PNMR | Significant Other Observable Inputs (Level 2) | Corporate |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 205,029 |
Fair value of plan assets at end of year | 215,323 | 205,029
PNMR | Significant Other Observable Inputs (Level 2) | U.S. Government |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 25,311 |
Fair value of plan assets at end of year | 25,969 | 25,311
PNMR | Significant Other Observable Inputs (Level 2) | Municipals |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 13,970 |
Fair value of plan assets at end of year | 11,438 | 13,970
PNMR | Significant Other Observable Inputs (Level 2) | Other funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 64,162 |
Fair value of plan assets at end of year | 65,220 | 64,162
PNMR | Significant Unobservable Inputs (Level 3) |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 390 |
Fair value of plan assets at end of year | 212 | 390
PNMR | Significant Unobservable Inputs (Level 3) | Cash and cash equivalents |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
PNMR | Significant Unobservable Inputs (Level 3) | International funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
PNMR | Significant Unobservable Inputs (Level 3) | Domestic value |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
PNMR | Significant Unobservable Inputs (Level 3) | Domestic growth |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
PNMR | Significant Unobservable Inputs (Level 3) | Other funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
PNMR | Significant Unobservable Inputs (Level 3) | Corporate |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 390 | 797
Actual return on assets sold during the period | 1 | 1
Actual return on assets still held at period end | (8) | 21
Purchases | 102 | 0
Sales | (273) | (429)
Fair value of plan assets at end of year | 212 | 390
PNMR | Significant Unobservable Inputs (Level 3) | U.S. Government |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
PNMR | Significant Unobservable Inputs (Level 3) | Municipals |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
PNMR | Significant Unobservable Inputs (Level 3) | Other funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 0 |
Fair value of plan assets at end of year | 0 | 0
PNMR | Significant Unobservable Inputs (Level 3) | Private equity funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 352 |
Fair value of plan assets at end of year | 191 | 352
PNMR | Significant Unobservable Inputs (Level 3) | Hedge funds |  |
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] |  |
Fair value of plan assets at beginning of year | 38 |
Fair value of plan assets at end of year | $ 21 | $ 38

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