Variable Interest Entities (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($) MW	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) MW	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Jan. 31, 2016 USD ($)
Results of Operations
Operating revenues	$ 505,851	$ 729,888	$ 1,527,084	$ 1,673,736
Operating expenses	419,199	547,125	1,249,011	1,336,513
Earnings attributable to non-controlling interest	5,058	4,172	14,172	10,897
Financial Position
Current assets	489,227		489,227		$ 410,978
Assets	10,050,841	9,028,890	10,050,841	9,028,890	9,257,377
Current liabilities	1,478,573		1,478,573		890,370
Owners’ equity – non-controlling interest	$ 51,173		$ 51,173		52,994
San Juan Generating Station | Coal supply
Variable Interest Entity [Line Items]
Cash used to support bank letter or credit arrangement						$ 30,300
PNM
Variable Interest Entity [Line Items]
Number of megawatts purchased (in megawatts) | MW	64.1		64.1
Results of Operations
Operating revenues	$ 350,334	597,337	$ 1,118,741	1,312,800
Operating expenses	319,638	457,422	955,726	1,078,434
Earnings attributable to non-controlling interest	5,058	4,172	14,172	10,897
Financial Position
Current assets	414,625		414,625		345,645
Assets	6,731,852		6,731,852		6,272,166
Current liabilities	1,028,881		1,028,881		692,155
Owners’ equity – non-controlling interest	51,173		51,173		52,994
PNM | Valencia
Variable Interest Entity [Line Items]
Payment for fixed costs	5,100	5,000	15,200	14,600
Payment for variable costs	1,400	700	$ 4,100	1,100
Long-term contract option to purchase, ownership percentage (up to)			50.00%
Long-term contract option to purchase, purchase price - percentage of adjusted NBV			50.00%
Long-term contract option to purchase, purchase price - percentage of FMV			50.00%
Results of Operations
Operating revenues	6,679	5,640	$ 19,427	15,670
Operating expenses	1,621	1,468	5,255	4,773
Earnings attributable to non-controlling interest	5,058	$ 4,172	14,172	$ 10,897
Financial Position
Current assets	4,162		4,162		3,429
Net property, plant, and equipment	47,963		47,963		50,094
Assets	52,125		52,125		53,523
Current liabilities	952		952		529
Owners’ equity – non-controlling interest	$ 51,173		$ 51,173		$ 52,994
PNM | Purchased through May 2028 | Valencia
Variable Interest Entity [Line Items]
Number of megawatts purchased (in megawatts) | MW	155		155