Variable Interest Entities - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) MW	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Jan. 31, 2016 USD ($)
Results of Operations
Earnings attributable to non-controlling interest	$ 15,490	$ 14,013	$ 14,241
Financial Position
Current assets	324,600	377,479
Total assets	8,666,885	7,939,854	7,298,774
Current liabilities	664,213	977,662
Owners’ equity – non-controlling interest	55,405	59,009
Public Service Company of New Mexico
Results of Operations
Earnings attributable to non-controlling interest	15,490	14,013	14,241
Financial Position
Current assets	266,689	322,128
Total assets	6,060,133	5,581,033
Current liabilities	495,902	594,332
Owners’ equity – non-controlling interest	$ 55,405	59,009
Public Service Company of New Mexico | Valencia
Variable Interest Entity [Line Items]
Number of megawatts purchased (in megawatts) | MW	155
Payment for fixed charges	$ 19,800	20,000	19,900
Payment for variable charges	$ 1,900	1,400	1,200
Purchase price, percentage of the book value reduced by related indebtedness	50.00%
Purchase price, percentage of fair market value	50.00%
Results of Operations
Operating revenues	$ 21,624	21,297	21,073
Operating expenses	6,134	7,284	6,832
Earnings attributable to non-controlling interest	15,490	14,013	$ 14,241
Financial Position
Current assets	3,042	3,911
Net property, plant and equipment	52,908	55,744
Total assets	55,950	59,655
Current liabilities	545	646
Owners’ equity – non-controlling interest	$ 55,405	$ 59,009
Public Service Company of New Mexico | Maximum | Valencia
Variable Interest Entity [Line Items]
Option to purchase a percentage of the plant or VIE (up to )	50.00%
NM Capital | Coal Supply | San Juan Generating Station
Financial Position
Issuance in letters of credit	$ 30,300			$ 30,300