Financing - Schedule of Short-Term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Short-term Debt [Line Items]
Balance Outstanding	$ 236,000	$ 181,400
PNM
Short-term Debt [Line Items]
Balance Outstanding	48,900	178,800
Revolving Credit Facility \| PNM \| PNM Revolving Credit Facility \| Line of credit
Short-term Debt [Line Items]
Balance Outstanding	$ 0	$ 138,800
Weighted Average Interest Rate	0.00%	5.04%
Revolving Credit Facility \| PNM \| PNM New Mexico Credit Facility \| Line of credit
Short-term Debt [Line Items]
Balance Outstanding	$ 40,000	$ 40,000
Weighted Average Interest Rate	5.25%	5.08%
Revolving Credit Facility \| PNM \| PNM Commercial Paper Notes \| Line of credit
Short-term Debt [Line Items]
Balance Outstanding	$ 8,900	$ 0
Weighted Average Interest Rate	4.18%	0.00%
Revolving Credit Facility \| TXNM \| TXNM Revolving Credit Facility \| Line of credit
Short-term Debt [Line Items]
Balance Outstanding	$ 0	$ 2,600
Weighted Average Interest Rate	0.00%	5.16%
Revolving Credit Facility \| TXNM \| TXNM Commercial Paper Notes \| Line of credit
Short-term Debt [Line Items]
Balance Outstanding	$ 187,100	$ 0
Weighted Average Interest Rate	4.41%	0.00%

The effective interest rate at the end of the reporting period.

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- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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