Commitments and Contingencies - The Clean Air Act (Details)	Jun. 30, 2022 T	Feb. 25, 2019 parts_per_billion	Oct. 01, 2015 parts_per_billion	Sep. 30, 2015 parts_per_billion	Dec. 31, 1999 state
Clean Air Act related to regional haze
Public Utilities, Commitments And Contingencies [Line Items]
Number of states to address regional haze (in states) | state					50
Potential to emit tons per year of visibility impairing pollution (in tons, more than) | T	250
Maximum | PNM | San Juan Generating Station and Four Corners
Public Utilities, Commitments And Contingencies [Line Items]
Government standard emission limit (in ozone parts per million) | parts_per_billion		75	70	75