XML 101 R80.htm IDEA: XBRL DOCUMENT v3.25.2
Pension and Other Postretirement Benefit Plans - Schedule of Net Periodic Benefit Costs (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
PNM | Pension Plan        
Components of Net Periodic Benefit Cost        
Service cost $ 0 $ 0 $ 0 $ 0
Interest cost 5,385 5,428 10,770 10,855
Expected return on plan assets (7,459) (7,757) (14,917) (15,514)
Amortization of net (gain) loss 3,124 2,662 6,247 5,323
Amortization of prior service cost 0 0 0 0
Net Periodic Benefit Cost (Income) 1,050 333 2,100 664
PNM | OPEB Plan        
Components of Net Periodic Benefit Cost        
Service cost 0 0 0 0
Interest cost 566 597 1,133 1,194
Expected return on plan assets (1,384) (1,391) (2,768) (2,782)
Amortization of net (gain) loss 0 0 0 0
Amortization of prior service cost 0 0 0 0
Net Periodic Benefit Cost (Income) (818) (794) (1,635) (1,588)
PNM | Executive Retirement Program        
Components of Net Periodic Benefit Cost        
Service cost 0 0 0 0
Interest cost 122 124 244 248
Expected return on plan assets 0 0 0 0
Amortization of net (gain) loss 47 50 94 100
Amortization of prior service cost 0 0 0 0
Net Periodic Benefit Cost (Income) 169 174 338 348
Texas-New Mexico Power Company | Pension Plan        
Components of Net Periodic Benefit Cost        
Service cost 0 0 0 0
Interest cost 536 554 1,072 1,107
Expected return on plan assets (733) (687) (1,466) (1,374)
Amortization of net (gain) loss 168 139 336 278
Amortization of prior service cost 0 0 0 0
Net Periodic Benefit Cost (Income) (29) 6 (58) 11
Texas-New Mexico Power Company | OPEB Plan        
Components of Net Periodic Benefit Cost        
Service cost 4 6 8 11
Interest cost 93 97 186 193
Expected return on plan assets (120) (128) (240) (257)
Amortization of net (gain) loss (124) (160) (248) (321)
Amortization of prior service cost 0 0 0 0
Net Periodic Benefit Cost (Income) $ (147) $ (185) $ (294) $ (374)