Employee Retirement Benefits (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Pension Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Service cost	$ 18	$ 15	$ 54	$ 47
Interest cost	24	25	73	76
Expected return on plan assets	(63)	(60)	(190)	(180)
Amortization of prior service cost (benefit)	0	3	1	4
Amortization of losses	0	0	0	0
Net periodic benefit (income) cost	(21)	(17)	(62)	(53)
Other Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Service cost	1	0	2	2
Interest cost	3	4	10	12
Expected return on plan assets	0	0	(1)	(1)
Amortization of prior service cost (benefit)	(1)	(1)	(2)	(2)
Amortization of losses	1	0	2	0
Net periodic benefit (income) cost	4	3	11	11
FPL [Member] | Pension Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Net periodic benefit (income) cost	(13)	(11)	(40)	(34)
FPL [Member] | Other Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Net periodic benefit (income) cost	$ 3	$ 2	$ 8	$ 8