Segment Information - Schedule of Gross Margin (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Gross margin	$ 740,455	$ 648,949	$ 606,727
Transmission and distribution costs	94,684	81,335	77,943
Depreciation and amortization	279,128	260,805	253,124
Utility margin	1,261,614	1,135,020	1,075,771
Electricity, Generation
Segment Reporting Information [Line Items]
Energy production costs	147,347	143,931	137,977
Public Service Company of New Mexico
Segment Reporting Information [Line Items]
Gross margin	516,375	466,092	441,831
Transmission and distribution costs	58,278	49,846	49,534
Depreciation and amortization	180,812	170,365	165,325
Utility margin	902,812	830,234	794,667
Public Service Company of New Mexico | Electricity, Generation
Segment Reporting Information [Line Items]
Energy production costs	147,347	143,931	137,977
Texas-New Mexico Power Company
Segment Reporting Information [Line Items]
Gross margin	224,080	182,857	164,896
Transmission and distribution costs	36,406	31,489	28,409
Depreciation and amortization	98,316	90,440	87,799
Utility margin	358,802	304,786	281,104
Texas-New Mexico Power Company | Electricity, Generation
Segment Reporting Information [Line Items]
Energy production costs	0	0	0
Corporate and Other
Segment Reporting Information [Line Items]
Gross margin	0	0	0
Transmission and distribution costs	0	0	0
Depreciation and amortization	0	0	0
Utility margin	0	0	0
Corporate and Other | Electricity, Generation
Segment Reporting Information [Line Items]
Energy production costs	$ 0	$ 0	$ 0