Fair Value Measurements (Reconciliation of Changes in the Fair Value of Derivatives) (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
Realized and unrealized gains (losses): [Abstract]
Realized and unrealized gains (losses) reflected in operating revenues	$ 2		$ 53		$ 1		$ 281
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Gain (Loss) Included in Interest Expense	11				11
Unrealized gains (losses) reflected in operating revenues	1		76		32		189
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Unrealized Gain (Loss) Included in Interest Expense	11				11
Derivative Financial Instruments, Net [Member]
Reconciliation of changes in the fair value of derivatives measured based on significant unobservable inputs Roll Forward [Abstract]
Fair value of net derivatives based on significant unobservable inputs, beginning balance	522		589		566		486
Realized and unrealized gains (losses): [Abstract]
Included in Earnings	13	[1]	53	[1]	10	[2]	284	[2]
Included in regulatory assets and liabilities	(3)		2		(2)		6
Purchases	21		23		70		181
Settlements	(23)		(58)		(56)		(182)
Issuances	(30)		(23)		(94)		(200)
Transfers in	(114)	[3]	0	[3]	(114)	[3]	16	[3]
Transfers out	(2)	[3]	(11)	[3]	4	[3]	(16)	[3]
Fair value of net derivatives based on significant unobservable inputs, ending balance	384		575		384		575
The amount of gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to derivatives still held at the reporting date	12	[4]	76	[4]	40	[5]	190	[5]
FPL [Member] | Derivative Financial Instruments, Net [Member]
Reconciliation of changes in the fair value of derivatives measured based on significant unobservable inputs Roll Forward [Abstract]
Fair value of net derivatives based on significant unobservable inputs, beginning balance	2		7		2		4
Realized and unrealized gains (losses): [Abstract]
Included in Earnings	0		0		0		0
Included in regulatory assets and liabilities	(3)		2		(2)		6
Purchases	0		0		0		0
Settlements	0		(2)		(1)		(3)
Issuances	0		0		0		0
Transfers in	0		0		0		0
Transfers out	0		0		0		0
Fair value of net derivatives based on significant unobservable inputs, ending balance	(1)		7		(1)		7
The amount of gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to derivatives still held at the reporting date	$ 0		$ 0		$ 0		$ 0

[1] For the three months ended June 30, 2013, realized and unrealized gains of approximately $2 million are reflected in the condensed consolidated statements of income in operating revenues and $11 million in interest expense. For the three months ended June 30, 2012, realized and unrealized gains of approximately $53 million are reflected in the condensed consolidated statements of income in operating revenues.

[2] For the six months ended June 30, 2013, realized and unrealized gains (losses) of approximately $1 million are reflected in the condensed consolidated statements of income in operating revenues, $11 million in interest expense and the balance is reflected in fuel, purchased power and interchange. For the six months ended June 30, 2012, realized and unrealized gains of approximately $281 million are reflected in the condensed consolidated statements of income in operating revenues and the balance is reflected in fuel, purchased power and interchange.

[3] Transfers into Level 3 were a result of decreased observability of market data and, in 2013, the use of a significant credit valuation adjustment. Transfers from Level 3 to Level 2 were a result of increased observability of market data. NEE's and FPL's policy is to recognize all transfers at the beginning of the reporting period.

[4] For the three months ended June 30, 2013, unrealized gains of less than $1 million are reflected in the condensed consolidated statements of income in operating revenues and approximately $11 million in interest expense. For the three months ended June 30, 2012, unrealized gains of approximately $76 million are reflected in the condensed consolidated statements of income in operating revenues.

[5] For the six months ended June 30, 2013, unrealized gains (losses) of approximately $32 million are reflected in the condensed consolidated statements of income in operating revenues, $11 million in interest expense and the balance is reflected in fuel, purchased power and interchange. For the six months ended June 30, 2012, unrealized gains of approximately $189 million are reflected in the condensed consolidated statements of income in operating revenues and the balance is reflected in fuel, purchased power and interchange.