Employee Retirement Benefits (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Pension Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Service cost	$ 20	$ 18	$ 40	$ 35
Interest cost	28	20	57	41
Expected return on plan assets	(78)	(69)	(156)	(138)
Amortization of prior service benefit	0	0	0	0
Special termination benefits	16	0	16	0
Net periodic benefit (income) cost	(14)	(31)	(43)	(62)
Postretirement Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Service cost	0	0	0	1
Interest cost	3	2	5	3
Expected return on plan assets	0	0	0	0
Amortization of prior service benefit	(4)	(4)	(8)	(8)
Special termination benefits	0	0	0	0
Net periodic benefit (income) cost	(1)	(2)	(3)	(4)
FPL [Member] | Pension Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Net periodic benefit (income) cost	(18)	(20)	(36)	(40)
FPL [Member] | Postretirement Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Net periodic benefit (income) cost	$ (1)	$ (2)	$ (2)	$ (3)