Employee Retirement Benefits - Additional Disclosures (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Fair value measurements of plan assets [Abstract]
Fair value	$ 3,122	[1]	$ 3,233	[1]
Components of net periodic benefit income (cost) recognized in OCI [Abstract]
Total	(45)		2		22
Employee contribution plans [Abstract]
Defined contribution expense	42		34		38
Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	834	[1]	860	[1]
Significant Other Observable Inputs (Level 2) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	2,181	[1]	2,362	[1]
Significant Unobservable Inputs (Level 3) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	107	[1]	11	[1]
Equity Securities [Member]
Fair value measurements of plan assets [Abstract]
Fair value	756	[1],[2]	806	[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	750	[1],[2]	800	[1],[3]
Foreign investments	258		293
Equity Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	5	[1],[2]	6	[1],[3]
Equity Securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	1	[1],[2]	0	[1],[3]
Equity commingled vehicles [Member]
Fair value measurements of plan assets [Abstract]
Fair value	568	[1],[4]	680	[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	568	[1],[4]	669	[1],[5]
Foreign investments	185		219
Equity commingled vehicles [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	0	[1],[4]	11	[1],[5]
U.S. Government and municipal bonds [Member]
Fair value measurements of plan assets [Abstract]
Fair value	135	[1]	95	[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	84	[1]	60	[1]
U.S. Government and municipal bonds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	51	[1]	35	[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	325	[1],[6]	335	[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	325	[1],[6]	335	[1],[7]
Foreign investments	58		47
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	318	[1]	263	[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	318	[1]	263	[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	586	[1],[8]	744	[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	586	[1],[8]	744	[1],[9]
Foreign investments	61		56
Short-term commingled vehicles	85		206
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	265	[1]	310	[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	265	[1]	310	[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	169	[1],[10]
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]
Limited Partnerships [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	63	[1],[10]
Foreign investments	31
Alternative investments	94
Unfunded commitments	24
Limited Partnerships [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	106	[1],[10]
Alternative Investments [Member]
Fair value measurements of plan assets [Abstract]
Lockup period, low end	1
Lockup period, high end	3
Redemption notification period	30-90 day
Pension Benefits [Member]
Fair value measurements of plan assets [Abstract]
Fair value	3,122		3,233		3,028
Expected benefit payments, net of government drug subsidy [Abstract]
2012	162
2013	162
2014	162
2015	162
2016	167
2017 - 2021	850
Net periodic benefit (income) cost [Abstract]
Service cost	64		59		51
Interest cost	98		102		109
Expected return on plan assets	(238)		(241)		(239)
Amortization of transition obligation	0		0		0
Amortization of prior service benefit	(3)		(3)		(3)
Amortization of gains	0		1		(23)
SERP settlements	0		1		0
Special termination benefits	0		13		0
Net periodic benefit (income) cost	(79)		(68)		(105)
Components of net periodic benefit income (cost) recognized in OCI [Abstract]
Prior service cost (net of $2 tax benefit)	0		0
Net gains (losses) (net of $32 tax benefit, none, $2 tax expense and $1 tax expense, respectively)	(45)		1
Amortization of prior service benefit	(1)		(1)
Amortization of transition obligation	0		0
Total	(46)		0
Tax effects on components of net periodic benefit income (cost) recognized in OCI [Abstract]
Tax expense (benefit) related to net gains (losses)	(32)		0
Components of net periodic benefit (income) cost recognized in regulatory assets (liabilities) [Abstract]
Prior service cost	1		1
Unrecognized (gains) losses	217		(35)
Amortization of prior service benefit	2		2
Amortization of transition obligation	0		0
Total	220		(32)
Weighted-average assumptions used to determine net periodic benefit (income) cost [Abstract]
Discount rate (in hundredths)	5.00%		5.50%		6.90%
Salary increase (in hundredths)	4.00%		4.00%		4.00%
Expected long-term rate of return (in hundredths)	7.75%	[11]	7.75%	[11]	7.75%	[11]
Other Benefits [Member]
Fair value measurements of plan assets [Abstract]
Fair value	28		32		32
Anticipated payment for eligible retiree medical expenses on behalf of the other benefits plan during 2011	26
Expected benefit payments, net of government drug subsidy [Abstract]
2012	33
2013	36
2014	36
2015	30
2016	30
2017 - 2021	144
Net periodic benefit (income) cost [Abstract]
Service cost	6		6		5
Interest cost	21		23		24
Expected return on plan assets	(2)		(2)		(3)
Amortization of transition obligation	3		3		4
Amortization of prior service benefit	0		0		0
Amortization of gains	0		0		0
SERP settlements	0		0		0
Special termination benefits	0		0		0
Net periodic benefit (income) cost	28		30		30
Components of net periodic benefit income (cost) recognized in OCI [Abstract]
Prior service cost (net of $2 tax benefit)	(3)		0
Net gains (losses) (net of $32 tax benefit, none, $2 tax expense and $1 tax expense, respectively)	3		2
Amortization of prior service benefit	0		0
Amortization of transition obligation	1		0
Total	1		2
Tax effects on components of net periodic benefit income (cost) recognized in OCI [Abstract]
Tax expense (benefit) related to prior service cost	(2)
Tax expense (benefit) related to net gains (losses)	2		1
Weighted-average assumptions used to determine net periodic benefit (income) cost [Abstract]
Discount rate (in hundredths)	5.25%		5.50%		6.90%
Salary increase (in hundredths)	4.00%		4.00%		4.00%
Expected long-term rate of return (in hundredths)	8.00%	[11]	8.00%	[11]	8.00%	[11]
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	17	[1]	20	[1]
Foreign investments	4		5
Other Benefits [Member] | Debt security commingled vehicles [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair value measurements of plan assets [Abstract]
Fair value	11		12
SERP and Other Benefits [Member]
Components of net periodic benefit (income) cost recognized in regulatory assets (liabilities) [Abstract]
Prior service cost	12		0
Unrecognized (gains) losses	7		(9)
Amortization of prior service benefit	0		0
Amortization of transition obligation	(2)		(2)
Total	$ 17		$ (11)

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

[2] Includes foreign investments of $258 million.

[3] Includes foreign investments of $293 million.

[4] Includes foreign investments of $185 million.

[5] Includes foreign investments of $219 million.

[6] Includes foreign investments of $58 million.

[7] Includes foreign investments of $47 million.

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

[9] Includes foreign investments of $56 million and $206 million of short-term commingled vehicles.

[10] Includes alternative investments of $94 million, of which $31 million were foreign investments. Fair values have been estimated using net asset value per share of the investments. These investments primarily have a one- to three-year lockup and are redeemable on either a quarterly or annual basis with a 30 to 90 day redemption notification requirement and have unfunded commitments of $24 million.

[11] 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.