Employee Retirement Benefits - Plan Assets, Benefit Obligations and Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Other Postretirement Benefits Plan [Member]
Change in pension benefit obligation:
Service cost	$ 1	$ 1	$ 2
Interest cost	9	5	4
Special termination benefits	0	0	0
Funded status:
Prepaid (accrued) benefit cost	(231)	(237)
Pension Benefits [Member]
Change in pension plan assets:
Plan assets, beginning balance	4,543	5,688
Actual return on plan assets	591	(820)
Benefit payments	(237)	(325)
Plan assets, ending balance	4,897	4,543	5,688
Change in pension benefit obligation:
Obligation, beginning balance	2,711	3,445
Service cost	64	86	90
Interest cost	132	77	64
Special termination benefits	0	(52)	0
Plan amendments	0	(3)
Actuarial losses (gains) – net(b)	115	(627)
Benefit payments	(237)	(325)
Obligation, ending balance	2,785	2,711	$ 3,445
Funded status:
Prepaid (accrued) benefit cost	2,112	1,832
Accumulated benefit obligation	2,719	2,650
FPL [Member] | Other Postretirement Benefits Plan [Member]
Funded status:
Prepaid (accrued) benefit cost	(101)	(115)
FPL [Member] | Pension Benefits [Member]
Funded status:
Prepaid (accrued) benefit cost	$ 1,853	$ 1,732