Derivative Instruments, Gains (losses) recorded in condensed consolidated financial statements (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2011		Jun. 30, 2010		Jun. 30, 2011		Jun. 30, 2010
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on commodity contracts, recorded as regulatory assets and or liabilities on the balance sheet due to regulatory treatment	$ (68)		$ 63		$ (68)		$ (392)
Interest rate swaps [Member] | Derivatives designated as cash flow hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in OCI	(119)		(72)		(118)		(106)
Gains (losses) reclassified from AOCI to net income	(24)	[1]	(9)	[1]	(43)	[1]	(26)	[1]
Gains (losses) recognized in income					0		0
Commodity contracts [Member] | Derivatives designated as cash flow hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in OCI	0		0		0		19
Gains (losses) reclassified from AOCI to net income	14	[2]	32	[2]	19	[2]	68	[2]
Gains (losses) recognized in income					0		1	[2]
Foreign currency swaps [Member] | Derivatives designated as cash flow hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in OCI	10		8		(6)		4
Gains (losses) reclassified from AOCI to net income	7	[3]	8	[3]	(4)	[4]	6	[3]
Gains (losses) recognized in income					0		0
Foreign currency swaps [Member] | Derivatives designated as cash flow hedges [Member] | Gains (losses) included in interest expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) reclassified from AOCI to net income	(1)		(1)		(3)		(1)
Derivatives designated as cash flow hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in OCI	(109)		(64)		(124)		(83)
Gains (losses) reclassified from AOCI to net income	(3)		31		(28)		48
Gains (losses) recognized in income					0		1
Commodity contracts [Member] | Derivatives not designated as hedging instruments [Member] | Gains (losses) included in operating revenues [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in income	154	[5]	(9)	[5]	2	[5]	261	[5]
Commodity contracts [Member] | Derivatives not designated as hedging instruments [Member] | Gains (losses) included in fuel, purchased power and interchange [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in income	23		27		(2)		94
Foreign currency swaps [Member] | Derivatives not designated as hedging instruments [Member] | Gains (losses) included in Other - net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in income	2		7		(3)		5
Interest rate contracts [Member] | Derivatives not designated as hedging instruments [Member] | Gains (losses) included in Other - net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in income	4		0		4		0
Derivatives not designated as hedging instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in income	183		25		1		360
Derivatives designated as fair value hedges [Member] | Gains (losses) included in interest expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in income	$ 9		$ 4		$ 3		$ 4
Number of instruments held	3		2		3		2

[1] Included in interest expense.

[2] Included in operating revenues.

[3] Loss of approximately $1 million is included in interest expense and the balance is included in other - net.

[4] Loss of approximately $3 million is included in interest expense and the balance is included in other - net.

[5] In addition, for both the three and six months ended June 30, 2011, FPL recorded approximately $68 million of losses related to commodity contracts as regulatory assets on its condensed consolidated balance sheets. For the three and six months ended June 30, 2010, FPL recorded approximately $63 million of gains and $392 million of losses, respectively, related to commodity contracts as regulatory liabilities and regulatory assets, respectively, on its condensed consolidated balance sheets.