Employee Retirement Benefits (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Pension Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Service cost	$ 18	$ 16	$ 36	$ 33
Interest cost	24	25	48	49
Expected return on plan assets	(59)	(60)	(119)	(119)
Amortization of transition obligation	0	0	0	0
Amortization of prior service cost (benefit)	2	1	4	2
Amortization of losses	0	0	1	0
Special termination benefits	12	0	12	0
Net periodic benefit (income) cost	(3)	(18)	(18)	(35)
Other Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Service cost	1	1	2	3
Interest cost	4	5	8	9
Expected return on plan assets	0	0	0	(1)
Amortization of transition obligation	0	1	0	1
Amortization of prior service cost (benefit)	(1)	0	(2)	1
Amortization of losses	0	0	1	0
Special termination benefits	0	0	0	0
Net periodic benefit (income) cost	4	7	9	13
FPL [Member] | Pension Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Net periodic benefit (income) cost	(2)	(11)	(12)	(23)
FPL [Member] | Other Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Net periodic benefit (income) cost	$ 3	$ 5	$ 6	$ 10