Equity Method Investment - Summarized Financial Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Statement [Abstract]
Operating Revenues	$ 2,249,555	$ 1,779,873	$ 1,523,012
Balance Sheet Related Disclosures [Abstract]
Net property, plant, and equipment	372,988	248,856
Total assets	9,257,377	8,666,885	7,939,854
Total PNMR common stockholders’ equity	2,191,932	2,167,524
NMRD
Income Statement [Abstract]
Operating Revenues	12,505	12,738	10,366
Operating expenses	9,591	9,733	7,476
Net earnings	2,914	3,005	$ 2,890
Balance Sheet Related Disclosures [Abstract]
Current assets	8,357	10,729
Net property, plant, and equipment	169,440	166,495
Non-current assets	9,631	2,289
Total assets	187,428	179,513
Current liabilities	5,822	824
Non-current liabilities	366	373
Total PNMR common stockholders’ equity	$ 181,240	$ 178,316