Commitments and Contingencies Environmental Requirements - Air (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) area
Implementation of the National Ambient Air Quality Standard for sulfur dioxide [Member] | Harrington Units 1 and 2 [Member]
Loss Contingencies [Line Items]
Exception to areas near generating plants attaining the SO2 NAAQS | area	1
Number of years unclassifiable areas will be monitored	3 years
Capital Addition Purchase Commitments [Member] | Regional Haze Rules [Member] | Tolk Units 1 and 2 [Member]
Loss Contingencies [Line Items]
Liability for estimated cost to comply with regulation | $	$ 600