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, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Realized and unrealized gains (losses): [Abstract]
Realized and unrealized gains (losses) reflected in operating revenues	$ 53		$ 92		$ 281		$ 1
Unrealized gains (losses) reflected in operating revenues	76		89		189		3
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	589		104		486		296
Realized and unrealized gains (losses): [Abstract]
Included in Earnings	53	[1]	95	[1]	284	[2]	13	[2]
Included in regulatory assets and liabilities	2		2		6		2
Purchases	23		53		181		141
Settlements	(58)		(58)		(182)		(103)
Issuances	(23)		(38)		(200)		(190)
Transfers in	0	[3]	1	[3]	16	[4]	2	[4]
Transfers out	(11)	[3]	(4)	[3]	(16)	[4]	(6)	[4]
Fair value of net derivatives based on significant unobservable inputs, ending balance	575		155		575		155
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	76	[5]	89	[5]	190	[6]	8	[6]
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	7		5		4		7
Realized and unrealized gains (losses): [Abstract]
Included in Earnings	0		0		0	[2]	0	[2]
Included in regulatory assets and liabilities	2		2		6		2
Purchases	0		0		0		0
Settlements	(2)		(2)		(3)		(4)
Issuances	0		0		0		0
Transfers in	0		0		0	[4]	0	[4]
Transfers out	0		0		0	[4]	0	[4]
Fair value of net derivatives based on significant unobservable inputs, ending balance	7		5		7		5
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	[6]	$ 0	[6]

[1] For the three months ended June 30, 2012 and 2011, $53 million and $92 million, respectively, of realized and unrealized gains (losses) are reflected in the condensed consolidated statements of income in operating revenues and the balance is reflected in fuel, purchased power and interchange.

[2] For the six months ended June 30, 2012 and 2011, $281 million and less than $1 million, respectively, of realized and unrealized gains (losses) are reflected in the condensed consolidated statements of income in operating revenues and the balance is reflected in fuel, purchased power and interchange.

[3] For the three months ended June 30, 2012 and 2011, transfers into Level 3 were a result of decreased observability of market data and 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 six months ended June 30, 2012 and 2011, transfers into Level 3 were a result of decreased observability of market data and 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.

[5] For the three months ended June 30, 2012 and 2011, $76 million and $89 million, respectively, of unrealized gains (losses) are reflected in the condensed consolidated statements of income in operating revenues

[6] For the six months ended June 30, 2012 and 2011, $189 million and $3 million, respectively, of unrealized gains (losses) are reflected in the condensed consolidated statements of income in operating revenues and the balance is reflected in fuel, purchased power and interchange.