Exit Activities (Narrative) (Details) - Retention Benefits - USD ($) $ in Millions	3 Months Ended		21 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024
Restructuring Cost and Reserve [Line Items]
Cost deferred	$ 3	$ 5
D.E. Karn Generating Complex and J.H. Campbell Generating Units | Retention incentive program
Restructuring Cost and Reserve [Line Items]
Regulatory asset collection period	3 years		3 years
J.H. Campbell Generating Units
Restructuring Cost and Reserve [Line Items]
Expected cost	$ 50		$ 50
J.H. Campbell Generating Units | Retention incentive program
Restructuring Cost and Reserve [Line Items]
Cost deferred			$ 38