v3.26.3
Accumulated Other Comprehensive Income (Loss) (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Accumulated Other Comprehensive Income (Loss) [Roll Forward]        
Beginning balance $ 3,602,408 $ 3,216,794 $ 3,448,006 $ 2,583,285
Total Other Comprehensive Income (Loss) 20 1,639 1,027 1,954
Ending balance 3,685,983 3,461,345 3,685,983 3,461,345
Total        
Accumulated Other Comprehensive Income (Loss) [Roll Forward]        
Beginning balance (25,809) (75,393) (26,816) (75,708)
Amounts reclassified from AOCI (pre-tax)     1,282 3,512
Income tax impact of amounts reclassified     (326) (892)
Other OCI changes (pre-tax)     95 (893)
Income tax impact of other OCI changes     (24) 227
Total Other Comprehensive Income (Loss) 20 1,639 1,027 1,954
Ending balance (25,789) (73,754) (25,789) (73,754)
Fair Value Adjustment for Cash Flow Hedges        
Accumulated Other Comprehensive Income (Loss) [Roll Forward]        
Beginning balance     (1,113) 0
Amounts reclassified from AOCI (pre-tax)     141 0
Income tax impact of amounts reclassified     (36) 0
Other OCI changes (pre-tax)     0 (1,538)
Income tax impact of other OCI changes     0 391
Total Other Comprehensive Income (Loss)     105 (1,147)
Ending balance (1,008) (1,147) (1,008) (1,147)
PNM        
Accumulated Other Comprehensive Income (Loss) [Roll Forward]        
Beginning balance 2,581,447 2,210,809 2,441,668 2,184,198
Total Other Comprehensive Income (Loss) (15) 926 922 3,101
Ending balance 2,708,542 2,313,442 2,708,542 2,313,442
PNM | Total        
Accumulated Other Comprehensive Income (Loss) [Roll Forward]        
Beginning balance (24,766) (73,533) (25,703) (75,708)
Amounts reclassified from AOCI (pre-tax)     1,141 3,512
Income tax impact of amounts reclassified     (290) (892)
Other OCI changes (pre-tax)     95 645
Income tax impact of other OCI changes     (24) (164)
Total Other Comprehensive Income (Loss) (15) 926 922 3,101
Ending balance (24,781) (72,607) (24,781) (72,607)
PNM | Unrealized Gains on Available-for-Sale Debt Securities        
Accumulated Other Comprehensive Income (Loss) [Roll Forward]        
Beginning balance     218 214
Amounts reclassified from AOCI (pre-tax)     (366) (611)
Income tax impact of amounts reclassified     93 155
Other OCI changes (pre-tax)     95 645
Income tax impact of other OCI changes     (24) (164)
Total Other Comprehensive Income (Loss)     (202) 25
Ending balance 16 239 16 239
PNM | Pension Liability Adjustment        
Accumulated Other Comprehensive Income (Loss) [Roll Forward]        
Beginning balance     (25,921) (75,922)
Amounts reclassified from AOCI (pre-tax)     1,507 4,123
Income tax impact of amounts reclassified     (383) (1,047)
Other OCI changes (pre-tax)     0 0
Income tax impact of other OCI changes     0 0
Total Other Comprehensive Income (Loss)     1,124 3,076
Ending balance $ (24,797) $ (72,846) $ (24,797) $ (72,846)