Fair Value Measurements (Reconciliation of Change in Fair Value of Derivatives, Significant Unobservable Inputs) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value Net Assets Liabilities Measured On Recurring Basis Gain Loss Included In Interest Expense	$ (79)
Realized and unrealized gains (losses):
Realized and unrealized gains (losses) reflected in operating revenues			302		220
Unrealized gains (losses) reflected in operating revenues, for derivatives still held at the reporting date	328		330		157
Derivative Financial Instruments, Net [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of derivatives based on significant unobservable inputs beginning balance	622		566		486
Realized and unrealized gains (losses):
Realized and unrealized gains (losses) included in earnings	(77)	[1]	299	[1]	218	[1]
Realized and unrealized gains (losses) included in other comprehensive income	18		0		0
Realized and unrealized gains (losses) included in regulatory assets and liabilities	7		0		5
Purchases	55		101		273
Settlements	194		(55)		(181)
Issuances	(122)		(173)		(243)
Transfers in(b)	80	[2]	(120)	[2]	20	[2]
Transfers out(b)	(155)	[2]	4	[2]	(12)	[2]
Fair value of derivatives based on significant unobservable inputs ending balance	622		622		566
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(c)	248	[3]	329	[3]	152	[3]
FPL [Member] | Derivative Financial Instruments, Net [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of derivatives based on significant unobservable inputs beginning balance	0		2		4
Realized and unrealized gains (losses):
Realized and unrealized gains (losses) included in earnings	0		0		0
Realized and unrealized gains (losses) included in other comprehensive income	0		0
Realized and unrealized gains (losses) included in regulatory assets and liabilities	7		0		5
Purchases	0		0		(7)
Settlements	(2)		(2)		0
Issuances	0		0		0
Transfers in(b)	0		0		0
Transfers out(b)	0		0		0
Fair value of derivatives based on significant unobservable inputs ending balance	5		0		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(c)	$ 0		$ 0		$ 0

[1] For the year ended December 31, 2014, $79 million of realized and unrealized losses are reflected in the consolidated statements of income in interest expense and the balance is primarily reflected in operating revenues. For the year December 31, 2013, $302 million of realized and unrealized gains are reflected in the consolidated statements of income in operating revenues and the balance is primarily reflected in interest expense. For the year ended December 31, 2012, $220 million of realized and unrealized gains are reflected in the consolidated statements of income in operating revenues and the balance is reflected in fuel, purchased power and interchange.

[2] Transfers into Level 3 were a result of decreased observability of market data and, in 2013, a significant credit valuation adjustment. 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 years ended December 31, 2014 and 2013, $328 million and $330 million of unrealized gains are reflected in the consolidated statements of income in operating revenues and the balance is reflected in interest expense. For the year ended December 31, 2012, $157 million of unrealized gains are reflected in the consolidated statements of income in operating revenues and the balance is reflected in fuel, purchased power and interchange.