Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 2,583,285	$ 2,399,051	$ 2,244,926
Total Other Comprehensive Income (Loss)	48,892	(12,868)	3,208
Ending balance	3,448,006	2,583,285	2,399,051
PNM
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	2,184,198	2,000,775	1,960,324
Total Other Comprehensive Income (Loss)	50,005	(9,203)	7,830
Ending balance	2,441,668	2,184,198	2,000,775
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(75,708)	(62,840)	(66,048)
Amounts reclassified from AOCI (pre-tax)	63,480	2,106	6,864
Income tax impact of amounts reclassified	(16,124)	(535)	(1,743)
Other OCI changes (pre-tax)	2,059	(19,355)	(2,565)
Income tax impact of other OCI changes	(523)	4,916	652
Total Other Comprehensive Income (Loss)	48,892	(12,868)	3,208
Ending balance	(26,816)	(75,708)	(62,840)
Total \| PNM
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(75,708)	(66,505)	(74,335)
Amounts reclassified from AOCI (pre-tax)	63,480	(8,242)	(2,423)
Income tax impact of amounts reclassified	(16,124)	2,094	616
Other OCI changes (pre-tax)	3,551	(4,095)	12,918
Income tax impact of other OCI changes	(902)	1,040	(3,281)
Total Other Comprehensive Income (Loss)	50,005	(9,203)	7,830
Ending balance	(25,703)	(75,708)	(66,505)
Unrealized Gains on Available-for-Sale Securities \| PNM
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	214	10,652	7,422
Amounts reclassified from AOCI (pre-tax)	(785)	(13,108)	(7,199)
Income tax impact of amounts reclassified	199	3,330	1,828
Other OCI changes (pre-tax)	791	(885)	11,529
Income tax impact of other OCI changes	(201)	225	(2,928)
Total Other Comprehensive Income (Loss)	4	(10,438)	3,230
Ending balance	218	214	10,652
Pension Liability Adjustment \| PNM
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(75,922)	(77,157)	(81,757)
Amounts reclassified from AOCI (pre-tax)	64,265	4,866	4,776
Income tax impact of amounts reclassified	(16,323)	(1,236)	(1,212)
Other OCI changes (pre-tax)	2,760	(3,210)	1,389
Income tax impact of other OCI changes	(701)	815	(353)
Total Other Comprehensive Income (Loss)	50,001	1,235	4,600
Ending balance	(25,921)	(75,922)	(77,157)
Fair Value Adjustment for Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	0	3,665	8,287
Amounts reclassified from AOCI (pre-tax)	0	10,348	9,287
Income tax impact of amounts reclassified	0	(2,629)	(2,359)
Other OCI changes (pre-tax)	(1,492)	(15,260)	(15,483)
Income tax impact of other OCI changes	379	3,876	3,933
Total Other Comprehensive Income (Loss)	(1,113)	(3,665)	(4,622)
Ending balance	$ (1,113)	$ 0	$ 3,665

TXNM ENERGY INC 10-K