Commitments and Contingencies (Insurance) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($)
Insurance [Abstract]
Maximum obtainable amount of private liability insurance available under Price-Anderson Act	$ 500
Amount of secondary financial protection liability insurance coverage per incident	15,800
Potential retrospective assessments under secondary financial protection system	1,161
Potential retrospective assessments under secondary financial protection system payable per incident per year	173
Amount of coverage per occurrence per site for property damage, decontamination and premature decommissioning risks	2,750
Amount of sublimit for non nuclear perils per occurrence per site under nuclear insurance mutual companies for property damage decontamination and premature decommissioning risks	$ 1,500
Coinsurance, percent	10.00%
Coinsurance, limit of coverage per loss per site occurrence	$ 400
Potential retrospective assessment, limited insurance coverage per occurrence per site, nuclear insurance mutual companies, property damage decontamination and premature decommissioning risks	161
Seabrook Station Insurance [Member]
Insurance [Abstract]
Potential retrospective assessment recoverable from minority interest for nuclear liability secondary financial protection	20
Potential retrospective assessment recoverable from minority interest for property damage, decontamination and premature decommissioning risks	2
Duane Arnold Energy Center Insurance [Member]
Insurance [Abstract]
Potential retrospective assessment recoverable from minority interest for property damage, decontamination and premature decommissioning risks	2
St Lucie Unit No 2 Insurance [Member]
Insurance [Abstract]
Potential retrospective assessment recoverable from minority interest for nuclear liability secondary financial protection	25
Potential retrospective assessment recoverable from minority interest for property damage, decontamination and premature decommissioning risks	4
FPL [Member]
Insurance [Abstract]
Potential retrospective assessments under secondary financial protection system	664
Potential retrospective assessments under secondary financial protection system payable per incident per year	99
Potential retrospective assessment, limited insurance coverage per occurrence per site, nuclear insurance mutual companies, property damage decontamination and premature decommissioning risks	102
Duane Arnold Energy Center Insurance [Member]
Insurance [Abstract]
Maximum obtainable amount of private liability insurance available under Price-Anderson Act	100
Amount of sublimit for non nuclear perils per occurrence per site under nuclear insurance mutual companies for property damage decontamination and premature decommissioning risks	$ 50