Asset Retirement Obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Asset Retirement Obligations [Line Items]
ARO liabilities related to nuclear decommissioning	72.00%
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning balance	$ 223,377	$ 234,146	$ 183,421
Liabilities incurred	0	0	1,781
Liabilities settled	(3,482)	0	(142)
Accretion expense	10,218	10,767	9,308
Revisions to estimated cash flows	15,418	(21,536)	39,778
Ending balance	245,531	223,377	234,146
San Juan Generating Station
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Revisions to estimated cash flows		(21,500)	39,800
Palo Verde Nuclear Generating Station
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Revisions to estimated cash flows	15,400
PNM
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning balance	222,549	233,383	182,718
Liabilities incurred	0	0	1,781
Liabilities settled	(3,482)	0	(142)
Accretion expense	10,148	10,702	9,248
Revisions to estimated cash flows	15,418	(21,536)	39,778
Ending balance	244,633	222,549	233,383
TNMP
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning balance	828	763	703
Liabilities incurred	0	0	0
Liabilities settled	0	0	0
Accretion expense	70	65	60
Revisions to estimated cash flows	0	0	0
Ending balance	$ 898	$ 828	$ 763