Employee Retirement Benefits (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Pension Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Service cost	$ 16	$ 16	$ 49	$ 48
Interest cost	25	25	74	74
Expected return on plan assets	(60)	(60)	(179)	(179)
Amortization of transition obligation	0	0	0	0
Amortization of prior service cost (benefit)	1	(1)	3	(2)
Net periodic benefit (income) cost	(18)	(20)	(53)	(59)
Other Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Service cost	1	2	4	5
Interest cost	4	5	13	16
Expected return on plan assets	0	(1)	(1)	(2)
Amortization of transition obligation	0	1	1	2
Amortization of prior service cost (benefit)	(1)	0	0	0
Net periodic benefit (income) cost	4	7	17	21
FPL [Member] | Pension Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Net periodic benefit (income) cost	(11)	(13)	(34)	(39)
FPL [Member] | Other Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Net periodic benefit (income) cost	$ 3	$ 5	$ 13	$ 16