Derivative Instruments (Balance Sheet Disclosure) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 3,952		$ 4,232
Derivative Liability, Fair Value, Gross Liability	3,330		3,345
Not Designated as Hedging Instrument [Member] | Commodity contracts [Member] | Current derivative assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	877		851
Derivative Liability, Fair Value, Gross Liability	383		321
Not Designated as Hedging Instrument [Member] | Commodity contracts [Member] | Current derivative liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	1,241		1,441
Derivative Liability, Fair Value, Gross Liability	1,598		1,838
Not Designated as Hedging Instrument [Member] | Commodity contracts [Member] | Non Current Derivative Assets Member [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	1,650		1,748
Derivative Liability, Fair Value, Gross Liability	722		715
Not Designated as Hedging Instrument [Member] | Commodity contracts [Member] | Noncurrent derivative liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	184		192
Derivative Liability, Fair Value, Gross Liability	453		438
Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Current derivative liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0		0
Derivative Liability, Fair Value, Gross Liability	91		0
Not Designated as Hedging Instrument [Member] | Foreign currency swaps [Member] | Current derivative liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0		0
Derivative Liability, Fair Value, Gross Liability	83		3
Not Designated as Hedging Instrument [Member] | Foreign currency swaps [Member] | Noncurrent derivative liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0		0
Derivative Liability, Fair Value, Gross Liability	0		30
Derivatives designated as hedging instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	70		76
Derivative Liability, Fair Value, Gross Liability	176		420
Derivatives designated as hedging instruments [Member] | Interest Rate Contract [Member] | Current derivative assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	27		30
Derivative Liability, Fair Value, Gross Liability	0		0
Derivatives designated as hedging instruments [Member] | Interest Rate Contract [Member] | Current derivative liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0		0
Derivative Liability, Fair Value, Gross Liability	61		104
Derivatives designated as hedging instruments [Member] | Interest Rate Contract [Member] | Non Current Derivative Assets Member [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	43		46
Derivative Liability, Fair Value, Gross Liability	0		0
Derivatives designated as hedging instruments [Member] | Interest Rate Contract [Member] | Noncurrent derivative liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0		0
Derivative Liability, Fair Value, Gross Liability	72		283
Derivatives designated as hedging instruments [Member] | Foreign currency swaps [Member] | Current derivative liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0		0
Derivative Liability, Fair Value, Gross Liability	22		5
Derivatives designated as hedging instruments [Member] | Foreign currency swaps [Member] | Noncurrent derivative liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0		0
Derivative Liability, Fair Value, Gross Liability	21		28
FPL [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	17		17
Derivative Liability, Fair Value, Gross Liability	63		32
FPL [Member] | Not Designated as Hedging Instrument [Member] | Commodity contracts [Member] | Current derivative assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	3	[1]	4	[1]
Derivative Liability, Fair Value, Gross Liability	1	[1]	0
FPL [Member] | Not Designated as Hedging Instrument [Member] | Commodity contracts [Member] | Current derivative liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	14	[2]	12	[2]
Derivative Liability, Fair Value, Gross Liability	44	[2]	32	[2]
FPL [Member] | Not Designated as Hedging Instrument [Member] | Commodity contracts [Member] | Non Current Derivative Assets Member [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0		1	[3]
Derivative Liability, Fair Value, Gross Liability	0		0
FPL [Member] | Not Designated as Hedging Instrument [Member] | Commodity contracts [Member] | Noncurrent derivative liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0		0
Derivative Liability, Fair Value, Gross Liability	18	[4]	0
FPL [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member] | Current derivative liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0		0
Derivative Liability, Fair Value, Gross Liability	0		0
FPL [Member] | Not Designated as Hedging Instrument [Member] | Foreign currency swaps [Member] | Current derivative liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0		0
Derivative Liability, Fair Value, Gross Liability	0		0
FPL [Member] | Not Designated as Hedging Instrument [Member] | Foreign currency swaps [Member] | Noncurrent derivative liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0		0
Derivative Liability, Fair Value, Gross Liability	$ 0		$ 0

[1] Included in current other assets on FPL's condensed consolidated balance sheets.

[2] Included in current other liabilities on FPL's condensed consolidated balance sheets.

[3] Included in noncurrent other assets on FPL's condensed consolidated balance sheets.

[4] Included in noncurrent other liabilities on FPL's condensed consolidated balance sheets.