Derivative Instruments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012		Dec. 31, 2011
Summary of derivative instruments by risk exposure, maximum maturity [Abstract]
Maximum length of time hedged in commodity cash flow hedges	December 2012
Maximum length of time hedged in interest rate cash flow hedges	December 2030
Maximum length of time hedged in foreign currency cash flow hedges	September 2030
Net fair values of mark-to-market derivative instrument assets (liabilities) [Abstract]
Current derivative assets	$ 858	[1]	$ 611	[1]
Noncurrent derivative assets	1,067	[2]	973	[2]
Current derivative liabilities	(1,347)	[3]	(1,090)	[3]
Noncurrent derivative liabilities	(690)	[4]	(541)	[4]
Total mark-to-market derivative instrument assets (liabilities)	(112)		(47)
Margin cash collateral received from counterparties - netted against current derivative assets	113		106
Margin cash collateral received from counterparties - netted against noncurrent derivative assets	160		109
Margin cash collateral provided to counterparties - netted against current derivative liabilities	114		112
Margin cash collateral provided to counterparties - netted against noncurrent derivative liabilities	56		79
Margin cash collateral received from counterparties that was not offset against derivative assets	27		22
Margin cash collateral provided to counterparties that was not offset against derivative liabilities	60		50
Total gain (loss) to be reclassified during next 12 months	$ (19)

[1] At March 31, 2012 and December 31, 2011, NEE's balances reflect the netting of approximately $113 million and $106 million (none at FPL), respectively, in margin cash collateral received from counterparties.

[2] At March 31, 2012 and December 31, 2011, NEE's balances reflect the netting of approximately $160 million and $109 million (none at FPL), respectively, in margin cash collateral received from counterparties.

[3] At March 31, 2012 and December 31, 2011, NEE's balances reflect the netting of approximately $114 million and $112 million (none at FPL), respectively, in margin cash collateral provided to counterparties.

[4] At March 31, 2012 and December 31, 2011, NEE's balances reflect the netting of approximately $56 million and $79 million (none at FPL), respectively, in margin cash collateral provided to counterparties.