Employee Retirement Benefits (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Pension Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Service cost	$ 21	$ 20	$ 42	$ 40
Interest cost	23	28	46	57
Expected return on plan assets	(80)	(78)	(161)	(156)
Amortization of prior service benefit	0	0	0	0
Amortization of actuarial loss	4	0	9	0
Special termination benefits	7	16	9	16
Net periodic benefit (income) cost	(25)	(14)	(55)	(43)
Postretirement Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Service cost	0	0	1	0
Interest cost	2	3	3	5
Expected return on plan assets	0	0	0	0
Amortization of prior service benefit	(4)	(4)	(8)	(8)
Amortization of actuarial loss	1	0	2	0
Special termination benefits	0	0	0	0
Net periodic benefit (income) cost	(1)	(1)	(2)	(3)
FPL [Member] | Pension Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Net periodic benefit (income) cost	(19)	(18)	(39)	(36)
FPL [Member] | Postretirement Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Net periodic benefit (income) cost	$ (1)	$ (1)	$ (1)	$ (2)