Employee Benefit Plans (Expected Benefit Payments) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014
Qualified Pension Plans [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	$ 584
2016	604
2017	616
2018	625
2019	626
2020-2024	3,107
Qualified Pension Plans [Member] \| Duke Energy Carolinas [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	175
2016	184
2017	195
2018	200
2019	194
2020-2024	924
Qualified Pension Plans [Member] \| Progress Energy [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	150
2016	158
2017	161
2018	165
2019	168
2020-2024	868
Qualified Pension Plans [Member] \| Duke Energy Progress [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	80
2016	85
2017	86
2018	87
2019	88
2020-2024	437
Qualified Pension Plans [Member] \| Duke Energy Florida [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	67
2016	70
2017	73
2018	76
2019	78
2020-2024	420
Qualified Pension Plans [Member] \| Duke Energy Ohio [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	34
2016	35
2017	34
2018	34
2019	34
2020-2024	168
Qualified Pension Plans [Member] \| Duke Energy Indiana [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	45
2016	46
2017	45
2018	46
2019	46
2020-2024	229
Non-Qualified Pension Plans [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	28
2016	27
2017	27
2018	24
2019	24
2020-2024	116
Non-Qualified Pension Plans [Member] \| Duke Energy Carolinas [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	2
2016	2
2017	2
2018	2
2019	2
2020-2024	6
Non-Qualified Pension Plans [Member] \| Progress Energy [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	8
2016	8
2017	8
2018	8
2019	8
2020-2024	38
Non-Qualified Pension Plans [Member] \| Duke Energy Progress [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	3
2016	3
2017	3
2018	3
2019	3
2020-2024	13
Non-Qualified Pension Plans [Member] \| Duke Energy Florida [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	4
2016	4
2017	4
2018	4
2019	4
2020-2024	19
Non-Qualified Pension Plans [Member] \| Duke Energy Ohio [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2020-2024	2
Non-Qualified Pension Plans [Member] \| Duke Energy Indiana [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2020-2024	2
Other Post-Retirement Benefit Plans [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	77
2016	77
2017	76
2018	74
2019	73
2020-2024	332
Other Post-Retirement Benefit Plans [Member] \| Duke Energy Carolinas [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	17
2016	18
2017	18
2018	19
2019	19
2020-2024	84
Other Post-Retirement Benefit Plans [Member] \| Progress Energy [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	30
2016	30
2017	29
2018	29
2019	29
2020-2024	132
Other Post-Retirement Benefit Plans [Member] \| Duke Energy Progress [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	16
2016	16
2017	15
2018	15
2019	15
2020-2024	70
Other Post-Retirement Benefit Plans [Member] \| Duke Energy Florida [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	14
2016	14
2017	14
2018	14
2019	13
2020-2024	61
Other Post-Retirement Benefit Plans [Member] \| Duke Energy Ohio [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	4
2016	4
2017	3
2018	3
2019	3
2020-2024	15
Other Post-Retirement Benefit Plans [Member] \| Duke Energy Indiana [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	10
2016	10
2017	9
2018	9
2019	8
2020-2024	$ 35

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Amount of benefits from a defined benefit plan expected to be paid in the five fiscal years 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 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (f)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920

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- Definition

Amount of benefits from a defined benefit plan expected to be paid 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.

+ References

+ Details

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- Definition

Amount of benefits from a defined benefit plan expected to be paid 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.

+ References

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- Definition

Amount of benefits from a defined benefit plan expected to be paid 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.

+ References

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- Definition

Amount of benefits from a defined benefit plan expected to be paid 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.

+ References

+ Details

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- Definition

Amount of benefits from a defined benefit plan expected to be paid 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.

+ References

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