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Financing - Financing Activities (Details) |  |  |  |  |  |  |  |  |  |  |  |  | 1 Months Ended | 3 Months Ended | 6 Months Ended |  |  |  |  |  |  |  |  |  |  |
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Jul. 31, 2025 USD ($) debtInstrument | Jul. 01, 2025 USD ($) | Jun. 30, 2025 USD ($) | Jun. 24, 2025 USD ($) d $ / shares shares | May 27, 2025 USD ($) shares | May 23, 2025 USD ($) d | May 19, 2025 USD ($) | May 18, 2025 USD ($) $ / shares shares | Jan. 31, 2025 | Aug. 05, 2024 USD ($) | Jun. 21, 2024 USD ($) | May 06, 2024 USD ($) | Jun. 30, 2025 USD ($) | Jul. 31, 2024 USD ($) | Jun. 30, 2025 USD ($) shares | Jun. 30, 2024 $ / shares shares | Jun. 30, 2025 USD ($) d shares | Jun. 30, 2024 USD ($) $ / shares | Jun. 30, 2026 USD ($) | Jul. 21, 2025 USD ($) | Apr. 23, 2025 USD ($) debtInstrument | Feb. 14, 2025 USD ($) | Jan. 21, 2025 USD ($) | Jul. 01, 2024 USD ($) | Jun. 10, 2024 USD ($) | Jun. 03, 2024 USD ($) | May 10, 2024 USD ($) | Mar. 28, 2024 USD ($) debtInstrument | Dec. 31, 2023 USD ($)
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revolving credit facilities repayments |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,662,500,000 | $ 1,519,800,000 |  |  |  |  |  |  |  |  |  |  |
Number of shares issued in transaction (in shares) | shares |  |  |  | 3,615,003 |  |  |  | 8,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sale of stock, price per share (in dollars per share) | $ / shares |  |  |  | $ 55.325 |  |  |  | $ 50.00 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Consideration received on transaction |  |  |  | $ 200,000,000 |  |  |  | $ 400,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of business days to register shares | d |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5 |  |  |  |  |  |  |  |  |  |  |  |
TXNM 2024 ATM Program |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Initial forward price (in shares) | shares |  |  |  |  | 1,104,641 |  |  |  |  |  |  |  |  |  | 1,100,000 |  | 1,100,000 |  |  |  |  |  |  |  |  |  |  |  |
Forward contract indexed to equity, settlement (in shares) |  |  |  |  | $ 49,600,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Issuance costs |  |  |  |  | $ 500,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
At-The-Market |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution agreement |  |  |  |  |  |  |  |  |  | $ 300,000,000 |  | $ 100,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
2024 Forward Sale Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of shares issued in transaction (in shares) | shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 262,025 |  |  |  |  |  |  |  |  |  |  |  |  |
Sale of stock, price per share (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 37.77 |  | $ 37.77 |  |  |  |  |  |  |  |  |  |  |
Treasury Lock Agreements | Cash Flow Hedging | Designated as Hedging Instrument |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative, notional amount |  |  | $ 730,000,000 |  |  |  |  |  |  |  |  |  | $ 730,000,000 |  | $ 730,000,000 |  | $ 730,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Average fixed interest rate |  |  | 4.18% |  |  |  |  |  |  |  |  |  | 4.18% |  | 4.18% |  | 4.18% |  |  |  |  |  |  |  |  |  |  |  |
Loss on derivative |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 2,500,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Minimum | Treasury Lock Agreements | Cash Flow Hedging | Designated as Hedging Instrument |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Term of contract |  |  | 5 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maximum | Treasury Lock Agreements | Cash Flow Hedging | Designated as Hedging Instrument |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Term of contract |  |  | 30 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revolving Credit Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revolving credit facilities repayments |  |  |  |  |  |  |  | 160,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loss on derivative |  | $ 1,600,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event | Minimum | Treasury Lock Agreements | Cash Flow Hedging | Designated as Hedging Instrument |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amortization of loss, period |  | 5 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event | Maximum | Treasury Lock Agreements | Cash Flow Hedging | Designated as Hedging Instrument |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amortization of loss, period |  | 30 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event | Revolving Credit Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revolving credit facilities repayments | $ 250,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
TXNM Merger Backstop Revolving Facility | Revolving Credit Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from lines of credit |  |  |  |  |  |  | $ 4,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Public Service Company of New Mexico |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity term over which financings require regulator approval (more than) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 18 months |  |  |  |  |  |  |  |  |  |  |  |
Revolving credit facilities repayments |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 756,900,000 | $ 804,800,000 |  |  |  |  |  |  |  |  |  |  |
Texas-New Mexico Power Company |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revolving credit facilities repayments |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 416,200,000 | $ 293,400,000 |  |  |  |  |  |  |  |  |  |  |
Texas-New Mexico Power Company | FMB Notes Due July 2024 | Senior Unsecured Noted, Pollution Control Revenue Bonds |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stated interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  | 4.03% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Repayments of unsecured debt |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 80,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Line of credit |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Ratio of debt to capital (less than or equal to) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 70.00% |  |  |  |  |  |  |  |  |  |  |  |
Line of credit | TXNM 2021 Delayed Draw Term Loan | Revolving Credit Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Repayments of debt |  |  |  |  |  |  |  |  |  |  | $ 449,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Line of credit | TXNM 2023 Term Loan | Revolving Credit Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Repayments of debt |  |  |  |  |  |  |  |  |  |  | 90,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Line of credit | PNM and TNMP |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Ratio of debt to capital (less than or equal to) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 65.00% |  |  |  |  |  |  |  |  |  |  |  |
Line of credit | Public Service Company of New Mexico | PNM 2024 Term Loan, Due November 2025 | Secured Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 200,000,000 |  |
Weighted Average Interest Rate |  |  | 5.32% |  |  |  |  |  |  |  |  |  | 5.32% |  | 5.32% |  | 5.32% |  |  |  |  |  |  |  |  |  |  |  |
Line of credit | Texas-New Mexico Power Company | TNMP Merger Backstop Term Loan | Secured Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  | $ 1,505,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, term |  |  |  |  |  |  |  | 364 days |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate during period |  |  |  |  |  |  |  |  |  |  |  |  | 5.42% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Unsecured Debt | TNMP First Mortgage Bonds | Subsequent Event |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,084,300,000 |  |  |  |  |  |  |  |  |
Unsecured Debt | TXNM Merger Backstop Revolving Facility | Revolving Credit Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Financing capacity |  |  |  |  |  |  |  | $ 910,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, term |  |  |  |  |  |  |  | 364 days |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Unsecured Debt | Public Service Company of New Mexico |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  | $ 250,000,000 |  |  |  |  |  |  |  |  |  | $ 250,000,000 |  | $ 250,000,000 |  | $ 250,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Unsecured Debt | Public Service Company of New Mexico | PNM July 2025 Note Purchase Agreement | Subsequent Event |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount | $ 350,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of debt issuances | debtInstrument | 2 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Unsecured Debt | Public Service Company of New Mexico | PNM July 2025 SUNs At Five Point Four Seven, Due July Twenty Thirty One | Subsequent Event |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount | $ 200,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stated interest rate | 5.47% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Unsecured Debt | Public Service Company of New Mexico | PNM July 2025 SUNs At Six Point Zero Three, Due July Twenty Thirty Six | Subsequent Event |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount | $ 150,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stated interest rate | 6.03% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Unsecured Debt | Public Service Company of New Mexico | PNM 2025 Note Purchase Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 300,000,000 |  |  |  |  |  |  |  |
Number of debt issuances | debtInstrument |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2 |  |  |  |  |  |  |  |
Unsecured Debt | Public Service Company of New Mexico | PNM 2025 Bond At Five Point Seven Five, Due June Twenty Thirty Two |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 125,000,000 |  |  |  |  |  |  |  |
Stated interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5.75% |  |  |  |  |  |  |  |
Unsecured Debt | Public Service Company of New Mexico | PNM 2025 Bond At Six Point One Three, Due June Twenty Thirty Seven |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 175,000,000 |  |  |  |  |  |  |  |
Stated interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 6.13% |  |  |  |  |  |  |  |
Unsecured Debt | Texas-New Mexico Power Company | TNMP First Mortgage Bonds |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  | $ 1,505,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Merger agreement, number of business days to offer prepayment of debt | d |  |  |  |  |  | 30 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Redemption price |  |  |  | 100.00% |  | 100.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt offered for prepayment |  |  |  | $ 1,084,300,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Merger agreement, number of business days to offer prepayment of debt after close of merger | d |  |  |  | 30 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Merger agreement, proposed debt extinguishment |  |  |  | $ 420,700,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Unsecured Debt | Texas-New Mexico Power Company | TNMP 2025 Bond At Five Point One Nine Percent |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 140,000,000 |  |  |  |  |  |  |
Stated interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5.19% |  |  |  |  |  |  |
Unsecured Debt | Texas-New Mexico Power Company | TNMP February 2025 Bond |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Repurchased face amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 40,000,000 |  |  |  |  |  |  |
Unsecured Debt | Texas-New Mexico Power Company | TNMP February 2025 Bond | Forecast |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Repurchased face amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 100,000,000 |  |  |  |  |  |  |  |  |  |
Unsecured Debt | Texas-New Mexico Power Company | TNMP 2024 Bond Purchase Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 285,000,000 |
Number of debt issuances | debtInstrument |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4 |
Unsecured Debt | Texas-New Mexico Power Company | TNMP 2024 Bond, 5.26%, Due March 28, 2029 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 32,000,000 |
Number of debt issuances | debtInstrument |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2 |
Stated interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5.26% |
Unsecured Debt | Texas-New Mexico Power Company | TNMP 2024 Bond, 5.55%, Due March 28, 2036 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 85,000,000 |
Stated interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5.55% |
Unsecured Debt | Texas-New Mexico Power Company | TNMP 2024 Bond, 5.65% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 40,000,000 |  |  |  |  |
Stated interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5.65% |  |  |  |  |
Unsecured Debt | Texas-New Mexico Power Company | TNMP 2024 Bond, 5.79% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 128,000,000 |  |  |  |  |
Stated interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5.79% |  |  |  |  |
Unsecured Debt | Texas-New Mexico Power Company | TNMP 2024 Bonds |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Repurchased face amount |  |  |  |  |  |  |  | $ 125,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Unsecured Debt | Texas-New Mexico Power Company | TNMP 2024 Bonds | Forecast |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Repurchased face amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 160,000,000 |  |  |  |  |  |  |  |  |  |
Notes Payable to Banks | Public Service Company of New Mexico | PNM 2025 Term Loan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 195,000,000 |  |  |  |  |  |
Stated interest rate |  |  | 5.32% |  |  |  |  |  |  |  |  |  | 5.32% |  | 5.32% |  | 5.32% |  |  |  |  |  |  |  |  |  |  |  |
Convertible Debt | Convertible Notes |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 500,000,000 |  |  |  |
Stated interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5.75% |  |  |  |
Conversion ratio |  |  |  |  |  |  |  |  | 0.0225005 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Convertible Debt | Convertible Notes - Option |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  | $ 50,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Bonds | PNM 2024 Term Loan, Due November 2025 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable interest rate |  |  | 5.32% |  |  |  |  |  |  |  |  |  | 5.32% |  | 5.32% |  | 5.32% |  |  |  |  |  |  |  |  |  |  |  |
Bonds | TXNM 2023 Delayed-Draw Term Loan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable interest rate |  |  | 5.78% |  |  |  |  |  |  |  |  |  | 5.78% |  | 5.78% |  | 5.78% |  |  |  |  |  |  |  |  |  |  |  |
Bonds | PNM 2025 Term Loan, Due July Twenty Twenty Six |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable interest rate |  |  | 5.32% |  |  |  |  |  |  |  |  |  | 5.32% |  | 5.32% |  | 5.32% |  |  |  |  |  |  |  |  |  |  |  |
Bonds | Public Service Company of New Mexico | 3.00% Pollution Control Revenue Bonds Due June 2038 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 37,000,000
Stated interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3.00%
Bonds | Public Service Company of New Mexico | 1.15% Pollution Control Revenue Bonds Due June 2038 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 125,000,000
Stated interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1.15%
Bonds | Public Service Company of New Mexico | Pollution Control Revenue Bonds Due June 2024 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 36,000,000
Stated interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3.00%
Bonds | Public Service Company of New Mexico | Pollution Control Revenue Bonds Due June 2029 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 198,000,000 |  |  |
Stated interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3.875% |  |  |

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