Employee Retirement Benefits (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Pension Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Service cost	$ 22	$ 20	$ 64	$ 60
Interest cost	23	28	69	86
Expected return on plan assets	(80)	(78)	(241)	(235)
Amortization of prior service benefit	(1)	0	(1)	(1)
Amortization of actuarial loss	4	0	13	0
Special termination benefits	4	1	13	17
Net periodic benefit (income) cost	(28)	(29)	(83)	(73)
Postretirement Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Service cost	0	0	1	1
Interest cost	3	3	6	7
Expected return on plan assets	0	0	0	0
Amortization of prior service benefit	(4)	(4)	(12)	(12)
Amortization of actuarial loss	0	0	2	0
Special termination benefits	0	0	0	0
Net periodic benefit (income) cost	(1)	(1)	(3)	(4)
FPL [Member] | Pension Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Net periodic benefit (income) cost	(19)	(18)	(58)	(53)
FPL [Member] | Postretirement Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Net periodic benefit (income) cost	$ (1)	$ (1)	$ (2)	$ (3)