Commitments And Contingencies (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Insurance
Insured public liability limit per nuclear incident	$ 12,600,000,000
Excess nuclear liability program coverage	12,200,000,000
Pro rata assessment for each reactor owned for each incident exceeding public liability insurance	117,500,000
Annual payment limit to pro rata assessments	17,500,000
Industry aggregate limit	3,200,000,000
NEIL sublimit for non-nuclear terrorist events	1,830,000,000
NEIL sublimit property damage losses	1,500,000,000
NEIL sublimit accidental outage recovery	328,000,000
Valuation and Qualifying Accounts [Abstract]
Loss exposure in excess of accrual, high estimate	92,000,000
Probable insurance recoveries	781,000,000	[1],[2]	813,000,000	[1],[2]
Reserves for legal matters	846,000,000	[3],[4]	810,000,000	[3],[4]
Unconditional Purchase Obligations [Abstract]
2013	68,000,000	[5]
2014	19,000,000	[5]
2015	5,000,000	[5]
2016	3,000,000	[5]
2017	2,000,000	[5]
Thereafter	18,000,000	[5]
Total	115,000,000	[5]
Duke Energy Carolinas [Member]
Insurance
Insured public liability limit per nuclear incident	12,600,000,000
Primary nuclear liability program coverage	375,000,000
Excess nuclear liability program coverage	12,200,000,000
Pro rata assessment for each reactor owned for each incident exceeding public liability insurance	117,500,000
Annual payment limit to pro rata assessments	17,500,000
Industry aggregate limit	3,200,000,000
NEIL sublimit for non-nuclear terrorist events	1,830,000,000
NEIL primary property insurance coverage per nuclear facility	500,000,000
NEIL primary property insurance deductible per occurrence obligation	2,500,000
NEIL sublimit property damage losses	1,500,000,000
NEIL sublimit accidental outage recovery	328,000,000
NEIL maximum potentional retroactive premium assessments for primary property insurance	45,000,000
NEIL maximum potentional retroactive premium assessments for excess property insurance	42,000,000
NEIL maximum potentional retroactive premium assessments for accidental outage insurance	22,000,000
NEIL share of maximum assessment amount included for jointly owned reactors	100.00%
Valuation and Qualifying Accounts [Abstract]
Loss exposure in excess of accrual, high estimate	28,000,000
Federal clean coal tax credits	125,000,000
New Source Review maximum civil penalties per day for each violation	32,500
Probable insurance recoveries	781,000,000	[1],[2]	813,000,000	[1],[2]
Reserves for legal matters	751,000,000	[3],[4]	801,000,000	[3],[4]
Duke Energy Carolinas [Member] | McGuire Nuclear Station [Member]
Insurance
NEIL excess property, decontamination and decommissioning liability insurance limits on each nuclear plant	1,000,000,000
NEIL excess property, decontamination and decommissioning liability insurance additional shared limits	1,000,000,000
NEIL accidental outage insurance coverage per week at each nuclear unit	3,500,000
NEIL accidental outage insurance deductible period	26
Percentage cost of original insurance coverage initial weeks are provided	100.00%
Initial weeks of insurance coverage	52
Percentage cost of original insurance coverage additional weeks are provided	80.00%
Additional weeks of insurance coverage	110
NEIL accidental outage insurance coverage policy limit	490,000,000
Duke Energy Carolinas [Member] | Oconee Nuclear Station [Member]
Insurance
NEIL excess property, decontamination and decommissioning liability insurance limits on each nuclear plant	1,000,000,000
NEIL excess property, decontamination and decommissioning liability insurance additional shared limits	1,000,000,000
NEIL accidental outage insurance coverage per week at each nuclear unit	2,800,000
NEIL accidental outage insurance deductible period	26
Percentage cost of original insurance coverage initial weeks are provided	100.00%
Initial weeks of insurance coverage	52
Percentage cost of original insurance coverage additional weeks are provided	80.00%
Additional weeks of insurance coverage	110
NEIL accidental outage insurance coverage policy limit	392,000,000
Duke Energy Carolinas [Member] | Catawba Nuclear Station [Member]
Insurance
NEIL excess property, decontamination and decommissioning liability insurance limits on each nuclear plant	2,250,000,000
NEIL accidental outage insurance coverage per week at each nuclear unit	3,500,000
NEIL accidental outage insurance deductible period	12
Percentage cost of original insurance coverage initial weeks are provided	100.00%
Initial weeks of insurance coverage	52
Percentage cost of original insurance coverage additional weeks are provided	80.00%
Additional weeks of insurance coverage	110
NEIL accidental outage insurance coverage policy limit	490,000,000
Progress Energy [Member]
Insurance
Insured public liability limit per nuclear incident	12,600,000,000
Excess nuclear liability program coverage	12,200,000,000
Pro rata assessment for each reactor owned for each incident exceeding public liability insurance	117,500,000
Annual payment limit to pro rata assessments	17,500,000
Industry aggregate limit	3,200,000,000
NEIL sublimit for non-nuclear terrorist events	1,830,000,000
NEIL sublimit property damage losses	1,500,000,000
NEIL sublimit accidental outage recovery	328,000,000
Valuation and Qualifying Accounts [Abstract]
Loss exposure in excess of accrual, high estimate	7,000,000
Reserves for legal matters	79,000,000	[3]	83,000,000	[3]
Unconditional Purchase Obligations [Abstract]
2013	68,000,000	[5]
2014	19,000,000	[5]
2015	5,000,000	[5]
2016	3,000,000	[5]
2017	2,000,000	[5]
Thereafter	18,000,000	[5]
Total	115,000,000	[5]
Progress Energy Carolinas [Member]
Insurance
Insured public liability limit per nuclear incident	12,600,000,000
Primary nuclear liability program coverage	375,000,000
Excess nuclear liability program coverage	12,200,000,000
Pro rata assessment for each reactor owned for each incident exceeding public liability insurance	117,500,000
Annual payment limit to pro rata assessments	17,500,000
Industry aggregate limit	3,200,000,000
NEIL sublimit for non-nuclear terrorist events	1,830,000,000
NEIL primary property insurance coverage per nuclear facility	500,000,000
NEIL primary property insurance deductible per occurrence obligation	10,000,000
NEIL excess property, decontamination and decommissioning liability insurance additional shared limits	1,000,000,000
NEIL sublimit property damage losses	1,500,000,000
NEIL sublimit accidental outage recovery	328,000,000
NEIL maximum potentional retroactive premium assessments for primary property insurance	27,000,000
NEIL maximum potentional retroactive premium assessments for excess property insurance	32,000,000
NEIL maximum potentional retroactive premium assessments for accidental outage insurance	19,000,000
NEIL share of maximum assessment amount included for jointly owned reactors	100.00%
Valuation and Qualifying Accounts [Abstract]
Loss exposure in excess of accrual, high estimate	3,000,000
Reserves for legal matters	12,000,000	[3]	11,000,000	[3]
Progress Energy Carolinas [Member] | Purchased power [Member] | Other Utilities [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, share of plant output being purchased	100.00%
2013	88,000,000
2014	90,000,000
2015	91,000,000
2016	92,000,000
2017	80,000,000
Thereafter	578,000,000
Progress Energy Carolinas [Member] | Robinson Nuclear Station [Member]
Insurance
NEIL excess property, decontamination and decommissioning liability insurance limits on each nuclear plant	750,000,000
NEIL accidental outage insurance coverage per week at each nuclear unit	3,500,000
NEIL accidental outage insurance deductible period	12
Percentage cost of original insurance coverage initial weeks are provided	100.00%
Initial weeks of insurance coverage	52
Percentage cost of original insurance coverage additional weeks are provided	80.00%
Additional weeks of insurance coverage	110
NEIL accidental outage insurance coverage policy limit	490,000,000
Progress Energy Carolinas [Member] | Brunswick Nuclear Station [Member]
Insurance
NEIL excess property, decontamination and decommissioning liability insurance limits on each nuclear plant	750,000,000
NEIL accidental outage insurance coverage per week at each nuclear unit	3,500,000
NEIL accidental outage insurance deductible period	12
Percentage cost of original insurance coverage initial weeks are provided	100.00%
Initial weeks of insurance coverage	52
Percentage cost of original insurance coverage additional weeks are provided	80.00%
Additional weeks of insurance coverage	110
NEIL accidental outage insurance coverage policy limit	490,000,000
Progress Energy Carolinas [Member] | Harris Nuclear Station [Member]
Insurance
NEIL excess property, decontamination and decommissioning liability insurance limits on each nuclear plant	750,000,000
NEIL accidental outage insurance coverage per week at each nuclear unit	3,500,000
NEIL accidental outage insurance deductible period	12
Percentage cost of original insurance coverage initial weeks are provided	100.00%
Initial weeks of insurance coverage	52
Percentage cost of original insurance coverage additional weeks are provided	80.00%
Additional weeks of insurance coverage	110
NEIL accidental outage insurance coverage policy limit	490,000,000
Progress Energy Florida [Member]
Insurance
Insured public liability limit per nuclear incident	12,600,000,000
Primary nuclear liability program coverage	375,000,000
Excess nuclear liability program coverage	12,200,000,000
Pro rata assessment for each reactor owned for each incident exceeding public liability insurance	117,500,000
Annual payment limit to pro rata assessments	17,500,000
Industry aggregate limit	3,200,000,000
NEIL sublimit for non-nuclear terrorist events	1,830,000,000
NEIL primary property insurance coverage per nuclear facility	500,000,000
NEIL primary property insurance deductible per occurrence obligation	10,000,000
NEIL excess property, decontamination and decommissioning liability insurance additional shared limits	1,000,000,000
NEIL sublimit property damage losses	1,500,000,000
NEIL sublimit accidental outage recovery	328,000,000
NEIL maximum potentional retroactive premium assessments for primary property insurance	11,000,000
NEIL maximum potentional retroactive premium assessments for excess property insurance	10,000,000
NEIL maximum potentional retroactive premium assessments for accidental outage insurance	6,000,000
NEIL share of maximum assessment amount included for jointly owned reactors	100.00%
Valuation and Qualifying Accounts [Abstract]
Loss exposure in excess of accrual, high estimate	4,000,000
Reserves for legal matters	47,000,000	[3],[6]	51,000,000	[3],[6]
Unconditional Purchase Obligations [Abstract]
Unrecorded unconditional purchase obligation, purchases	29,000,000		6,000,000		23,000,000
2013	68,000,000	[5]
2014	19,000,000	[5]
2015	5,000,000	[5]
2016	3,000,000	[5]
2017	2,000,000	[5]
Thereafter	18,000,000	[5]
Total	115,000,000	[5]
Progress Energy Florida [Member] | Purchased power [Member] | Other Utilities [Member]
Unconditional Purchase Obligations [Abstract]
2013	102,000,000
2014	102,000,000
2015	102,000,000
2016	71,000,000
2017	49,000,000
Thereafter	381,000,000
Progress Energy Florida [Member] | Purchased power [Member] | Qualified Facilities [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, share of plant output being purchased	100.00%
2013	309,000,000
2014	237,000,000
2015	244,000,000
2016	273,000,000
2017	288,000,000
Thereafter	2,440,000,000
Progress Energy Florida [Member] | Crystal River Unit 3 [Member]
Insurance
NEIL excess property, decontamination and decommissioning liability insurance limits on each nuclear plant	750,000,000
NEIL accidental outage insurance coverage per week at each nuclear unit	4,500,000
NEIL accidental outage insurance deductible period	12
Percentage cost of original insurance coverage initial weeks are provided	100.00%
Initial weeks of insurance coverage	52
Percentage cost of original insurance coverage additional weeks are provided	80.00%
Additional weeks of insurance coverage	71
NEIL accidental outage insurance coverage policy limit	490,000,000
Duke Energy Ohio [Member]
Valuation and Qualifying Accounts [Abstract]
Loss exposure in excess of accrual, high estimate	51,000,000
Duke Energy Ohio [Member] | Purchased power [Member] | Other Utilities [Member]
Unconditional Purchase Obligations [Abstract]
2013	316,000,000
2014	252,000,000
2015	80,000,000
Duke Energy Indiana [Member]
Valuation and Qualifying Accounts [Abstract]
Loss exposure in excess of accrual, high estimate	5,000,000
Federal clean coal tax credits	134,000,000
Reserves for legal matters	8,000,000	[3]	4,000,000	[3]
Paranapanema Lawsuit [Member]
Valuation and Qualifying Accounts [Abstract]
Additional assessment under resolutions promulgated by ANEEL	61,000,000
Fines imposed by ANEEL due to DEIGP's refusal to pay additional assessments	9,000,000
Escrow deposit made to court's registry for assessment under ANEEL Resolutions	33,000,000
Brazil Expansion Lawsuit [Member]
Valuation and Qualifying Accounts [Abstract]
Obligation to expand installed generation capacity, percent	15.00%
Crescent Litigation [Member]
Valuation and Qualifying Accounts [Abstract]
Amount of claim(s)	1,200,000,000
Asbestos Issue [Member] | Duke Energy Carolinas [Member]
Valuation and Qualifying Accounts [Abstract]
Number of nonmalignant asbestos related claims	111
Cumulative relief sought for nonmalignant asbestos related claims	27,000,000
Number of malignant asbestos related claims	49
Cumulative relief sought for malignant asbestos related claims	17,000,000
Asbestos-related injuries and damages reserves	751,000,000		801,000,000
Asbestos related injuries and damages self insured retention	476,000,000
Policy limit for potential future insurance recoveries for indemnification and medical cost claim payments in excess of self insured limit	935,000,000
Synthetic Fuels [Member] | Progress Energy [Member]
Valuation and Qualifying Accounts [Abstract]
Original judgment award	78,000,000
Prejudgment interest	55,000,000
Total Judgment	133,000,000
Judgment payment	154,000,000
Percentage of original claim to which plaintiff is entitled	59.00%
Damages awarded to plaintiff	90,000,000
Gain recognized in period	63,000,000
Synthetic Fuels [Member] | Progress Energy Carolinas [Member]
Valuation and Qualifying Accounts [Abstract]
Gain contingency asserted damage	113,000,000
Synthetic Fuels [Member] | Progress Energy Florida [Member]
Valuation and Qualifying Accounts [Abstract]
Gain contingency asserted damage	113,000,000
Minimum [Member]
Valuation and Qualifying Accounts [Abstract]
Estimated cost of complying with recently issued and proposed EPA regulations	5,000,000,000
Minimum [Member] | Purchased power [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, date of contract expiration	2013
Minimum [Member] | Progress Energy Carolinas [Member] | Purchased power [Member] | Other Utilities [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, date of contract expiration	2017
Minimum [Member] | Progress Energy Florida [Member] | Purchased power [Member] | Other Utilities [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, date of contract expiration	2017
Long-term contract for purchase of electric power, share of plant output being purchased	2.00%
Minimum [Member] | Progress Energy Florida [Member] | Purchased power [Member] | Qualified Facilities [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, date of contract expiration	2013
Minimum [Member] | Duke Energy Ohio [Member] | Purchased power [Member] | Other Utilities [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, date of contract expiration	2013
Long-term contract for purchase of electric power, share of plant output being purchased	1.00%
Minimum [Member] | Alaskan Global Warming Lawsuit [Member]
Valuation and Qualifying Accounts [Abstract]
Amount of claim(s)	95,000,000
Maximum [Member]
Valuation and Qualifying Accounts [Abstract]
Estimated cost of complying with recently issued and proposed EPA regulations	6,000,000,000
Maximum [Member] | Purchased power [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, date of contract expiration	2032
Maximum [Member] | Progress Energy Carolinas [Member] | Purchased power [Member] | Other Utilities [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, date of contract expiration	2032
Maximum [Member] | Progress Energy Florida [Member] | Purchased power [Member] | Other Utilities [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, date of contract expiration	2027
Long-term contract for purchase of electric power, share of plant output being purchased	100.00%
Maximum [Member] | Progress Energy Florida [Member] | Purchased power [Member] | Qualified Facilities [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, date of contract expiration	2025
Maximum [Member] | Duke Energy Ohio [Member] | Purchased power [Member] | Other Utilities [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, date of contract expiration	2015
Long-term contract for purchase of electric power, share of plant output being purchased	24.00%
Maximum [Member] | Alaskan Global Warming Lawsuit [Member]
Valuation and Qualifying Accounts [Abstract]
Amount of claim(s)	$ 400,000,000

[1] Insurance recoveries are classified in the respective Consolidated Balance Sheets in Other within Investments and Other Assets and Receivables.

[2] Relates to recoveries associated with aforementioned asbestos-related injuries and damages claims.

[3] Reserves are classified in the respective Consolidated Balance Sheets in Other within Deferred Credits and Other Liabilities and Other within Current Liabilities.

[4] Includes reserves for aforementioned asbestos-related injuries and damages claims.

[5] Represents estimated amounts for Progress Energy Florida's obligations primarily related to selected components of long lead time equipment at Levy as discussed under "Other Purchase Obligations."

[6] Includes workers' compensation claims.