Regulatory and Rate Matters - FERC Order 864 (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Public Utilities, General Disclosures [Line Items]
Electric operating revenues	$ 505,851	$ 729,888	$ 1,527,084	$ 1,673,736
Other current liabilities	89,727		89,727		$ 87,037
FERC Order 864
Public Utilities, General Disclosures [Line Items]
Electric operating revenues	(3,100)
Other current liabilities	3,100		3,100
Public Service Company of New Mexico
Public Utilities, General Disclosures [Line Items]
Electric operating revenues	350,334	$ 597,337	1,118,741	$ 1,312,800
Other current liabilities	54,491		54,491		$ 55,350
Public Service Company of New Mexico | FERC Order 864
Public Utilities, General Disclosures [Line Items]
Electric operating revenues	(3,100)
Other current liabilities	$ 3,100		$ 3,100