Employee Retirement Benefits - Net Periodic Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Pension Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Service cost	$ 90	$ 85	$ 80
Interest cost	64	92	114
Expected return on plan assets	(339)	(321)	(312)
Amortization of actuarial loss	24	18	0
Amortization of prior service benefit	(1)	(1)	(1)
Special termination benefits	0	16	19
Net periodic (income) cost	(162)	(111)	(100)
Other Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Service cost	2	1	1
Interest cost	4	8	9
Expected return on plan assets	0	0	0
Amortization of actuarial loss	5	3	0
Amortization of prior service benefit	(15)	(16)	(15)
Special termination benefits	0	0	0
Net periodic (income) cost	(4)	(4)	(5)
FPL [Member] | Pension Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Net periodic (income) cost	(108)	(84)	(61)
FPL [Member] | Other Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Net periodic (income) cost	$ (4)	$ (4)	$ (4)