Fair Value Measurements (Reconciliation of Changes in the Fair Value of Derivatives) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Realized and unrealized gains (losses): [Abstract]
Realized and unrealized gains (losses) reflected in operating revenues	$ (405)		$ (1)
Realized and unrealized gains (losses) reflected in interest expense	(15)
Unrealized gains (losses) reflected in operating revenues related to derivatives still held at the reporting date	(234)		31
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	622		566
Realized and unrealized gains (losses): [Abstract]
Included in Earnings	(423)	[1]	(3)	[1]
Included in regulatory assets and liabilities	4		1
Purchases	4		49
Settlements	266		(33)
Issuances	(19)		(64)
Transfers in	7	[2]	0	[2]
Transfers out	(1)	[2]	6	[2]
Fair value of net derivatives based on significant unobservable inputs, ending balance	460		522
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	(249)	[3]	32	[3]
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	0		2
Realized and unrealized gains (losses): [Abstract]
Included in Earnings	0		0
Included in regulatory assets and liabilities	4		1
Purchases	0		0
Settlements	(1)		(1)
Issuances	0		0
Transfers in	0		0
Transfers out	0		0
Fair value of net derivatives based on significant unobservable inputs, ending balance	3		2
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

[1] For the three months ended March 31, 2014, realized and unrealized losses of approximately $405 million are reflected in the condensed consolidated statements of income in operating revenues, $15 million in interest expense and the balance is reflected in fuel, purchased power and interchange. For the three months ended March 31, 2013, realized and unrealized losses are reflected in the condensed consolidated statements of income in fuel, purchased power and interchange.

[2] 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.

[3] For the three months ended March 31, 2014, unrealized losses of $234 million are reflected in the condensed consolidated statements of income in operating revenues and the balance is reflected in interest expense. For the three months ended March 31, 2013, unrealized gains of approximately $31 million are reflected in the condensed consolidated statements of income in operating revenues and the balance is reflected in fuel, purchased power and interchange.