Debt and Credit Facilities (Annual Maturities) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	$ 2,807us-gaap_LongTermDebtCurrent	$ 2,104us-gaap_LongTermDebtCurrent
Long-term Debt, Fiscal Year Maturity [Abstract]
2015	2,793
2016	2,980
2017	2,452
2018	3,207
2019	2,810
Thereafter	23,803
Total long-term debt, including current maturities	38,045
Other Debt Obligations [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	214
Duke Energy Carolinas [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	507	47
Long-term Debt, Fiscal Year Maturity [Abstract]
2015	507
2016	756
2017	116
2018	1,505
2019	5
Thereafter	5,502
Total long-term debt, including current maturities	8,391
Duke Energy Carolinas [Member] \| 5.300% October 2015 Maturity 1 [Member] \| First Mortgage Bonds [Member]
Current Maturities Of Long Term Debt [Abstract]
Maturity date	Oct. 30, 2015
Interest rate	5.30%
Current maturities of long-term debt	500
Progress Energy [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	1,507	485
Long-term Debt, Fiscal Year Maturity [Abstract]
2015	1,507
2016	614
2017	940
2018	515
2019	1,418
Thereafter	9,760
Total long-term debt, including current maturities	14,754
Duke Energy Progress [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	945	174
Long-term Debt, Fiscal Year Maturity [Abstract]
2015	945
2016	302
2017	453
2018	3
2019	606
Thereafter	3,892
Total long-term debt, including current maturities	6,201
Duke Energy Progress [Member] \| 5.150% April 2015 Maturity 2 [Member] \| First Mortgage Bonds [Member]
Current Maturities Of Long Term Debt [Abstract]
Maturity date	Apr. 30, 2015
Interest rate	5.15%
Current maturities of long-term debt	300
Duke Energy Progress [Member] \| 5.250% December 2015 Maturity 2 [Member] \| First Mortgage Bonds [Member]
Current Maturities Of Long Term Debt [Abstract]
Maturity date	Dec. 31, 2015
Interest rate	5.25%
Current maturities of long-term debt	400
Duke Energy Progress [Member] \| 0.108% January 2015 Maturity 1 [Member] \| Tax Exempt Bonds [Member]
Current Maturities Of Long Term Debt [Abstract]
Maturity date	Jan. 31, 2015
Interest rate	0.108%
Current maturities of long-term debt	243
Duke Energy Florida [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	562	11
Long-term Debt, Fiscal Year Maturity [Abstract]
2015	562
2016	12
2017	487
2018	512
2019	12
Thereafter	3,275
Total long-term debt, including current maturities	4,860
Duke Energy Florida [Member] \| 0.650% November 2015 Maturity 1 [Member] \| First Mortgage Bonds [Member]
Current Maturities Of Long Term Debt [Abstract]
Maturity date	Nov. 30, 2015
Interest rate	0.65%
Current maturities of long-term debt	250
Duke Energy Florida [Member] \| 5.100% December 2015 Maturity 1 [Member] \| First Mortgage Bonds [Member]
Current Maturities Of Long Term Debt [Abstract]
Maturity date	Dec. 31, 2015
Interest rate	5.10%
Current maturities of long-term debt	300
Duke Energy Ohio [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	157	47
Long-term Debt, Fiscal Year Maturity [Abstract]
2015	157
2016	57
2017	3
2018	28
2019	552
Thereafter	969
Total long-term debt, including current maturities	1,766
Duke Energy Ohio [Member] \| 0.375 % March 2015 Debt Maturing [Member] \| First Mortgage Bonds [Member]
Current Maturities Of Long Term Debt [Abstract]
Maturity date	Mar. 31, 2015
Interest rate	0.375%
Current maturities of long-term debt	150
Duke Energy Indiana [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	5	5
Long-term Debt, Fiscal Year Maturity [Abstract]
2015	5
2016	480
2017	3
2018	153
2019	62
Thereafter	3,088
Total long-term debt, including current maturities	3,791
Parent Company [Member] \| 3.350% April 2015 Debt Maturing [Member] \| Unsecured Debt [Member]
Current Maturities Of Long Term Debt [Abstract]
Maturity date	Apr. 30, 2015
Interest rate	3.35%
Current maturities of long-term debt	$ 450

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Including current and noncurrent portions, aggregate carrying amount of long-term borrowings as of the balance sheet date, excluding purchase accounting adjustments.

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Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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-Topic 210

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-Section S99

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Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

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Amount of long-term debt, after unamortized discount or premium, scheduled to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19,20)

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 470

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601

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-Name Accounting Standards Codification

-Topic 235

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-Section S99

-Paragraph 3

-Subparagraph (SX 210.12-04.(a))

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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