Financing - Schedule of Short-Term Debt (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Short-term Debt [Line Items]
Short-term debt	$ 232,000,000	$ 62,700,000
PNM
Short-term Debt [Line Items]
Short-term debt	185,900,000	7,400,000
Texas-New Mexico Power Company
Short-term Debt [Line Items]
Short-term debt	36,700,000	400,000
PNM Revolving Credit Facility | PNM
Short-term Debt [Line Items]
Short-term debt	145,900,000	7,400,000
Financing capacity	400,000,000
PNM New Mexico Credit Facility | PNM
Short-term Debt [Line Items]
Short-term debt	40,000,000	0
TNMP Revolving Credit Facility | Texas-New Mexico Power Company
Short-term Debt [Line Items]
Short-term debt	36,700,000	400,000
Financing capacity		75,000,000
PNMR Revolving Credit Facility
Short-term Debt [Line Items]
Short-term debt	9,400,000	$ 54,900,000
Financing capacity	$ 300,000,000