Commitments and Contingencies - PVNGS Liability and Insurance Matters (Details) - PNM - Palo Verde Nuclear Generating Station - Nuclear plant	9 Months Ended
	Sep. 30, 2023 USD ($) generatingUnit
Public Utilities, Commitments And Contingencies [Line Items]
Number of units | generatingUnit	3
Maximum potential assessment per incident	$ 37,700,000
Annual payment limitation related to incident	5,600,000
Aggregate amount of all risk insurance	2,800,000,000
Maximum amount under nuclear electric insurance limited	5,100,000
Maximum
Public Utilities, Commitments And Contingencies [Line Items]
Liability insurance coverage	16,500,000,000
Liability insurance coverage sublimit	2,250,000,000
Commercial providers
Public Utilities, Commitments And Contingencies [Line Items]
Liability insurance coverage	450,000,000
Industry Wide Retrospective Assessment Program
Public Utilities, Commitments And Contingencies [Line Items]
Liability insurance coverage	$ 16,100,000,000