Fair Value Measurements (Details) (Fair value measurements made on a recurring basis [Member], USD $) In Millions, unless otherwise specified	Mar. 31, 2012		Dec. 31, 2011
Cash equivalents:
Equity securities	$ 105		$ 159
Special use funds:
Equity securities	2,218		1,915
U.S. Government and municipal bonds	649		675
Corporate debt securities	462		516
Mortgage-backed securities	512		511
Other debt securities	40		47
Other investments:
Equity securities	10		4
U.S. Government and municipal bonds	9		8
Corporate debt securities	42		43
Mortgage-backed securities	42		33
Other	9		10
Derivatives:
Commodity contracts	1,882	[1]	1,520	[1]
Interest rate swaps	43	[1]	37	[1]
Foreign currency swaps			27	[1]
Derivatives:
Commodity contracts	1,704	[1]	1,302	[1]
Interest rate swaps	306	[1]	320	[1]
Foreign currency swaps	27	[1]	9	[1]
Fair value of investments in commingled funds whose underlying investments would be Level 1 if those investments were held directly by the registrant	1,226		1,086
Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1) [Member]
Cash equivalents:
Equity securities	105		159
Special use funds:
Equity securities	797		709
U.S. Government and municipal bonds	507		508
Corporate debt securities	0		0
Mortgage-backed securities	0		0
Other debt securities	1		0
Other investments:
Equity securities	10		4
U.S. Government and municipal bonds	9		8
Corporate debt securities	0		0
Mortgage-backed securities	0		0
Other	5		5
Derivatives:
Commodity contracts	3,115		2,448
Interest rate swaps	0		0
Foreign currency swaps			0
Derivatives:
Commodity contracts	3,237		2,588
Interest rate swaps	0		0
Foreign currency swaps	0		0
Significant Other Observable Inputs (Level 2) [Member]
Cash equivalents:
Equity securities	0		0
Special use funds:
Equity securities	1,421	[2]	1,206	[3]
U.S. Government and municipal bonds	142		167
Corporate debt securities	462		516
Mortgage-backed securities	512		511
Other debt securities	39		47
Other investments:
Equity securities	0		0
U.S. Government and municipal bonds	0		0
Corporate debt securities	42		43
Mortgage-backed securities	42		33
Other	4		5
Derivatives:
Commodity contracts	4,316		3,478
Interest rate swaps	43		37
Foreign currency swaps			27
Derivatives:
Commodity contracts	4,502		3,582
Interest rate swaps	306		320
Foreign currency swaps	27		9
Significant Unobservable Inputs (Level 3) [Member]
Cash equivalents:
Equity securities	0		0
Special use funds:
Equity securities	0		0
U.S. Government and municipal bonds	0		0
Corporate debt securities	0		0
Mortgage-backed securities	0		0
Other debt securities	0		0
Other investments:
Equity securities	0		0
U.S. Government and municipal bonds	0		0
Corporate debt securities	0		0
Mortgage-backed securities	0		0
Other	0		0
Derivatives:
Commodity contracts	1,307		1,071
Interest rate swaps	0		0
Foreign currency swaps			0
Derivatives:
Commodity contracts	718		585
Interest rate swaps	0		0
Foreign currency swaps	0		0
Netting [Member]
Cash equivalents:
Equity securities	0	[4]	0	[4]
Special use funds:
Equity securities	0	[4]	0	[4]
U.S. Government and municipal bonds	0	[4]	0	[4]
Corporate debt securities	0	[4]	0	[4]
Mortgage-backed securities	0	[4]	0	[4]
Other debt securities	0	[4]	0	[4]
Other investments:
Equity securities	0	[4]	0	[4]
U.S. Government and municipal bonds	0	[4]	0	[4]
Corporate debt securities	0	[4]	0	[4]
Mortgage-backed securities	0	[4]	0	[4]
Other	0	[4]	0	[4]
Derivatives:
Commodity contracts	(6,856)	[4]	(5,477)	[4]
Interest rate swaps	0	[4]	0	[4]
Foreign currency swaps			0	[4]
Derivatives:
Commodity contracts	(6,753)	[4]	(5,453)	[4]
Interest rate swaps	0	[4]	0	[4]
Foreign currency swaps	$ 0	[4]	$ 0	[4]

[1] See Note 2 for a reconciliation of net derivatives to NEE's and FPL's condensed consolidated balance sheets.

[2] At NEE, approximately $1,226 million ($1,106 million at FPL) are invested in commingled funds whose underlying investments would be Level 1 if those investments were held directly by NEE or FPL.

[3] At NEE, approximately $1,086 million ($979 million at FPL) are invested in commingled funds whose underlying investments would be Level 1 if those investments were held directly by NEE or FPL.

[4] Includes the effect of the contractual ability to settle contracts under master netting arrangements and margin cash collateral payments and receipts.