Early Plant Retirements - Pretax Expense (Details) - Facility Closing [Member] - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Byron Dresden [Member]
Accelerated depreciation		$ 1,805	$ 895
Accelerated nuclear fuel amortization		148	60
Operating and maintenance		(94)	255
Asset Retirement Obligation, Revision of Estimate	$ (13)	9	34
Contractual offset		(451)	(364)
Restructuring and Related Cost, Incurred Cost		$ 1,417	$ 880
Three Mile Island [Member]
Accelerated depreciation				$ 216
Accelerated nuclear fuel amortization				13
Operating and maintenance				0
Asset Retirement Obligation, Revision of Estimate				(53)
Contractual offset				0
Restructuring and Related Cost, Incurred Cost				$ 176