Employee Retirement Benefits - Additional Disclosures (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Fair value measurements of plan assets [Abstract]
Fair value	$ 3,385	[1]	$ 3,122	[1]
Components of net periodic benefit income (cost) recognized in OCI [Abstract]
Total	(28)		(45)		2
Employee contribution plans [Abstract]
Defined Contribution Plan, Cost Recognized	44		42		34
Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	999	[1]	834	[1]
Significant Other Observable Inputs (Level 2) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	2,246	[1]	2,181	[1]
Significant Unobservable Inputs (Level 3) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	140	[1]	107	[1]
Equity Securities [Member]
Fair value measurements of plan assets [Abstract]
Fair value	833	[1],[2]	756	[1],[3]
Equity Securities [Member] | Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	833	[1],[2]	750	[1],[3]
Foreign investments	308		258
Equity Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	0	[1],[2]	5	[1],[3]
Equity Securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	0	[1],[2]	1	[1],[3]
Equity commingled vehicles [Member]
Fair value measurements of plan assets [Abstract]
Fair value	590	[1],[4]	568	[1],[5]
Equity commingled vehicles [Member] | Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	0	[1],[4]	0	[1],[5]
Equity commingled vehicles [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	590	[1],[4]	568	[1],[5]
Foreign investments	204		185
Equity commingled vehicles [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	0	[1],[4]	0	[1],[5]
U.S. Government and municipal bonds [Member]
Fair value measurements of plan assets [Abstract]
Fair value	216	[1]	135	[1]
U.S. Government and municipal bonds [Member] | Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	166	[1]	84	[1]
U.S. Government and municipal bonds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	50	[1]	51	[1]
U.S. Government and municipal bonds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	0	[1]	0	[1]
Corporate debt securities [Member]
Fair value measurements of plan assets [Abstract]
Fair value	349	[1],[6]	325	[1],[7]
Corporate debt securities [Member] | Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	0	[1],[6]	0	[1],[7]
Corporate debt securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	349	[1],[6]	325	[1],[7]
Foreign investments	66		58
Corporate debt securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	0	[1],[6]	0	[1],[7]
Asset-backed securities [Member]
Fair value measurements of plan assets [Abstract]
Fair value	273	[1]	318	[1]
Asset-backed securities [Member] | Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	0	[1]	0	[1]
Asset-backed securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	273	[1]	318	[1]
Asset-backed securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	0	[1]	0	[1]
Debt security commingled vehicles [Member]
Fair value measurements of plan assets [Abstract]
Fair value	589	[1],[8]	586	[1],[9]
Debt security commingled vehicles [Member] | Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	0	[1],[8]	0	[1],[9]
Debt security commingled vehicles [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	589	[1],[8]	586	[1],[9]
Foreign investments	60		61
Short-term commingled vehicles	135		85
Debt security commingled vehicles [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	0	[1],[8]	0	[1],[9]
Convertible securities [Member]
Fair value measurements of plan assets [Abstract]
Fair value	261	[1]	265	[1]
Convertible securities [Member] | Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	0	[1]	0	[1]
Convertible securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	261	[1]	265	[1]
Convertible securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	0	[1]	0	[1]
Limited Partnerships [Member]
Fair value measurements of plan assets [Abstract]
Fair value	274	[1],[10]	169	[1],[11]
Limited Partnerships [Member] | Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	0	[1],[10]	0	[1],[11]
Limited Partnerships [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	134	[1],[10]	63	[1],[11]
Foreign investments	39		31
Alternative investments	107		94
Fixed income oriented commingled investment arrangments	90
Convertible security oriented limited partnership investments	77
Limited Partnerships [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	140	[1],[10]	106	[1],[11]
Pension Benefits [Member]
Fair value measurements of plan assets [Abstract]
Fair value	3,385		3,122		3,233
Expected benefit payments, net of government drug subsidy [Abstract]
2013	144
2014	144
2015	149
2016	153
2017	159
2018 - 2022	832
Net periodic benefit (income) cost [Abstract]
Service cost	65		64		59
Interest cost	98		98		102
Expected return on plan assets	(238)		(238)		(241)
Amortization of transition obligation	0		0		0
Amortization of prior service cost (benefit)	5		(3)		(3)
Amortization of loss	0		0		1
SERP settlements	3		0		1
Special termination benefits	0		0		13
Net periodic benefit (income) cost	(67)		(79)		(68)
Components of net periodic benefit income (cost) recognized in OCI [Abstract]
Prior service benefit (cost) (net of $3 tax benefit, none, none, $4 tax expense, $2 tax benefit and none), respectively	(6)		0		0
Net gains (losses) (net of $16 tax benefit, $32 tax benefit, none, $3 tax benefit, $2 tax expense and $1 tax expense, respectively)	(25)		(45)		1
Amortization of prior service benefit (cost)	1		(1)		(1)
Amortization of transition obligation	0		0		0
Total	(30)		(46)		0
Tax effects on components of net periodic benefit income (cost) recognized in OCI [Abstract]
Tax expense (benefit) related to prior service cost	(3)		0		0
Tax expense (benefit) related to net gains (losses)	(16)		(32)		0
Components of net periodic benefit (income) cost recognized in regulatory assets (liabilities) [Abstract]
Prior service cost (benefit)	17		1
Unrecognized (gains) losses	1		217
Amortization of prior service cost (benefit)	(3)		2
Amortization of transition obligation	0		0
Amortization of unrecognized losses	0		0
Total	15		220
Weighted-average assumptions used to determine net periodic benefit (income) cost [Abstract]
Discount rate (in hundredths)	4.65%		5.00%		5.50%
Salary increase (in hundredths)	4.00%		4.00%		4.00%
Expected long-term rate of return (in hundredths)	7.75%	[12]	7.75%	[12]	7.75%	[12]
Other Benefits [Member]
Fair value measurements of plan assets [Abstract]
Fair value	26		28		32
Anticipated payment for eligible retiree medical expenses on behalf of the other benefits plan during 2013	28
Expected benefit payments, net of government drug subsidy [Abstract]
2013	35
2014	35
2015	29
2016	28
2017	29
2018 - 2022	134
Net periodic benefit (income) cost [Abstract]
Service cost	5		6		6
Interest cost	18		21		23
Expected return on plan assets	(2)		(2)		(2)
Amortization of transition obligation	1		3		3
Amortization of prior service cost (benefit)	(1)		0		0
Amortization of loss	0		0		0
SERP settlements	0		0		0
Special termination benefits	0		0		0
Net periodic benefit (income) cost	21		28		30
Components of net periodic benefit income (cost) recognized in OCI [Abstract]
Prior service benefit (cost) (net of $3 tax benefit, none, none, $4 tax expense, $2 tax benefit and none), respectively	7		(3)		0
Net gains (losses) (net of $16 tax benefit, $32 tax benefit, none, $3 tax benefit, $2 tax expense and $1 tax expense, respectively)	(5)		3		2
Amortization of prior service benefit (cost)	0		0		0
Amortization of transition obligation	0		1		0
Total	2		1		2
Tax effects on components of net periodic benefit income (cost) recognized in OCI [Abstract]
Tax expense (benefit) related to prior service cost	4		(2)		0
Tax expense (benefit) related to net gains (losses)	(3)		2		1
Weighted-average assumptions used to determine net periodic benefit (income) cost [Abstract]
Discount rate (in hundredths)	4.53%	[13]	5.25%		5.50%
Salary increase (in hundredths)	4.00%		4.00%		4.00%
Expected long-term rate of return (in hundredths)	8.00%	[12]	8.00%	[12]	8.00%	[12]
Effect of one-percentage point increase in assumed health care cost trend rates on total service and interest cost components	1
Effect of one-percentage point decrease in assumed health care cost trend rates on total service and interest cost components	1
Other Benefits [Member] | Equity commingled vehicles [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	18	[1]	17	[1]
Foreign investments	4		4
Other Benefits [Member] | Debt security commingled vehicles [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	7		11
SERP and Other Benefits [Member]
Components of net periodic benefit (income) cost recognized in regulatory assets (liabilities) [Abstract]
Prior service cost (benefit)	(29)		12
Unrecognized (gains) losses	16		7
Amortization of prior service cost (benefit)	0		0
Amortization of transition obligation	(1)		(2)
Amortization of unrecognized losses	(3)		0
Total	(17)		17
FPL [Member]
Employee contribution plans [Abstract]
Defined Contribution Plan, Cost Recognized	29		28		26
FPL [Member] | Pension Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Net periodic benefit (income) cost	(43)		(51)		(42)
FPL [Member] | Other Benefits [Member]
Net periodic benefit (income) cost [Abstract]
Net periodic benefit (income) cost	$ 16		$ 21		$ 23

[1] See Note 4 for discussion of fair value measurement techniques and inputs.

[2] Includes foreign investments of $308 million.

[3] Includes foreign investments of $258 million.

[4] Includes foreign investments of $204 million.

[5] Includes foreign investments of $185 million.

[6] Includes foreign investments of $66 million.

[7] Includes foreign investments of $58 million.

[8] Includes foreign investments of $60 million and $135 million of short-term commingled vehicles.

[9] Includes foreign investments of $61 million and $85 million of short-term commingled vehicles.

[10] Includes fixed income oriented commingled investment arrangements of $90 million, convertible security oriented limited partnerships of $77 million and alternative investments of $107 million, of which $39 million were foreign investments. Fair values have been estimated using net asset value per share (NAV) of the investments. Those investments subject to certain restrictions have been classified as Level 3.

[11] Includes alternative investments of $94 million, of which $31 million were foreign investments. Fair values have been estimated using NAV of the investments.

[12] In developing the expected long-term rate of return on assets assumption for its plans, NEE evaluated input, including other qualitative and quantitative factors, from its actuaries and consultants, as well as information available in the marketplace. NEE considered different models, capital market return assumptions and historical returns for a portfolio with an equity/bond asset mix similar to its funds. NEE also considered its funds' historical compounded returns.

[13] Reflects a mid-year rate change due to cost remeasurement resulting from a plan amendment.