Commitments and Contingencies (Schedule of Environmental Loss Contingencies)(Details) (USD $) In Millions, unless otherwise specified
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12 Months Ended |
Dec. 31, 2014
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Dec. 31, 2013
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Dec. 31, 2012
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Accrual for Environmental Loss Contingencies [Roll Forward] |
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Beginning balance |
$ 79us-gaap_AccrualForEnvironmentalLossContingencies |
$ 75us-gaap_AccrualForEnvironmentalLossContingencies |
$ 61us-gaap_AccrualForEnvironmentalLossContingencies |
Provision/adjustments |
32duk_AmountAccruedDuringPeriodForEnvironmentalLossContingencies |
26duk_AmountAccruedDuringPeriodForEnvironmentalLossContingencies |
39duk_AmountAccruedDuringPeriodForEnvironmentalLossContingencies |
Cash reductions |
(14)us-gaap_AccrualForEnvironmentalLossContingenciesPayments |
(22)us-gaap_AccrualForEnvironmentalLossContingenciesPayments |
(25)us-gaap_AccrualForEnvironmentalLossContingenciesPayments |
Ending balance |
97us-gaap_AccrualForEnvironmentalLossContingencies |
79us-gaap_AccrualForEnvironmentalLossContingencies |
75us-gaap_AccrualForEnvironmentalLossContingencies |
Duke Energy Carolinas [Member] |
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Accrual for Environmental Loss Contingencies [Roll Forward] |
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Beginning balance |
11us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyCarolinasMember |
12us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyCarolinasMember |
12us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyCarolinasMember |
Provision/adjustments |
(1)duk_AmountAccruedDuringPeriodForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyCarolinasMember |
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1duk_AmountAccruedDuringPeriodForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyCarolinasMember |
Cash reductions |
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(1)us-gaap_AccrualForEnvironmentalLossContingenciesPayments / dei_LegalEntityAxis = duk_DukeEnergyCarolinasMember |
(1)us-gaap_AccrualForEnvironmentalLossContingenciesPayments / dei_LegalEntityAxis = duk_DukeEnergyCarolinasMember |
Ending balance |
10us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyCarolinasMember |
11us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyCarolinasMember |
12us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyCarolinasMember |
Progress Energy [Member] |
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Accrual for Environmental Loss Contingencies [Roll Forward] |
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Beginning balance |
27us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_ProgressEnergyMember |
33us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_ProgressEnergyMember |
23us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_ProgressEnergyMember |
Provision/adjustments |
1duk_AmountAccruedDuringPeriodForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_ProgressEnergyMember |
4duk_AmountAccruedDuringPeriodForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_ProgressEnergyMember |
19duk_AmountAccruedDuringPeriodForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_ProgressEnergyMember |
Cash reductions |
(11)us-gaap_AccrualForEnvironmentalLossContingenciesPayments / dei_LegalEntityAxis = duk_ProgressEnergyMember |
(10)us-gaap_AccrualForEnvironmentalLossContingenciesPayments / dei_LegalEntityAxis = duk_ProgressEnergyMember |
(9)us-gaap_AccrualForEnvironmentalLossContingenciesPayments / dei_LegalEntityAxis = duk_ProgressEnergyMember |
Ending balance |
17us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_ProgressEnergyMember |
27us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_ProgressEnergyMember |
33us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_ProgressEnergyMember |
Duke Energy Progress [Member] |
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Accrual for Environmental Loss Contingencies [Roll Forward] |
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Beginning balance |
8us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyProgressMember |
14us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyProgressMember |
11us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyProgressMember |
Provision/adjustments |
4duk_AmountAccruedDuringPeriodForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyProgressMember |
(1)duk_AmountAccruedDuringPeriodForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyProgressMember |
5duk_AmountAccruedDuringPeriodForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyProgressMember |
Cash reductions |
(7)us-gaap_AccrualForEnvironmentalLossContingenciesPayments / dei_LegalEntityAxis = duk_DukeEnergyProgressMember |
(5)us-gaap_AccrualForEnvironmentalLossContingenciesPayments / dei_LegalEntityAxis = duk_DukeEnergyProgressMember |
(2)us-gaap_AccrualForEnvironmentalLossContingenciesPayments / dei_LegalEntityAxis = duk_DukeEnergyProgressMember |
Ending balance |
5us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyProgressMember |
8us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyProgressMember |
14us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyProgressMember |
Duke Energy Florida [Member] |
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Accrual for Environmental Loss Contingencies [Roll Forward] |
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Beginning balance |
19us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyFloridaMember |
19us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyFloridaMember |
12us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyFloridaMember |
Provision/adjustments |
(3)duk_AmountAccruedDuringPeriodForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyFloridaMember |
5duk_AmountAccruedDuringPeriodForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyFloridaMember |
14duk_AmountAccruedDuringPeriodForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyFloridaMember |
Cash reductions |
(4)us-gaap_AccrualForEnvironmentalLossContingenciesPayments / dei_LegalEntityAxis = duk_DukeEnergyFloridaMember |
(5)us-gaap_AccrualForEnvironmentalLossContingenciesPayments / dei_LegalEntityAxis = duk_DukeEnergyFloridaMember |
(7)us-gaap_AccrualForEnvironmentalLossContingenciesPayments / dei_LegalEntityAxis = duk_DukeEnergyFloridaMember |
Ending balance |
12us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyFloridaMember |
19us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyFloridaMember |
19us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyFloridaMember |
Duke Energy Ohio [Member] |
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Accrual for Environmental Loss Contingencies [Roll Forward] |
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Beginning balance |
27us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyOhioMember |
15us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyOhioMember |
28us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyOhioMember |
Provision/adjustments |
28duk_AmountAccruedDuringPeriodForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyOhioMember |
20duk_AmountAccruedDuringPeriodForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyOhioMember |
5duk_AmountAccruedDuringPeriodForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyOhioMember |
Cash reductions |
(1)us-gaap_AccrualForEnvironmentalLossContingenciesPayments / dei_LegalEntityAxis = duk_DukeEnergyOhioMember |
(8)us-gaap_AccrualForEnvironmentalLossContingenciesPayments / dei_LegalEntityAxis = duk_DukeEnergyOhioMember |
(18)us-gaap_AccrualForEnvironmentalLossContingenciesPayments / dei_LegalEntityAxis = duk_DukeEnergyOhioMember |
Ending balance |
54us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyOhioMember |
27us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyOhioMember |
15us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyOhioMember |
Duke Energy Indiana [Member] |
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Accrual for Environmental Loss Contingencies [Roll Forward] |
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Beginning balance |
7us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyIndianaMember |
8us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyIndianaMember |
9us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyIndianaMember |
Provision/adjustments |
4duk_AmountAccruedDuringPeriodForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyIndianaMember |
1duk_AmountAccruedDuringPeriodForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyIndianaMember |
3duk_AmountAccruedDuringPeriodForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyIndianaMember |
Cash reductions |
(1)us-gaap_AccrualForEnvironmentalLossContingenciesPayments / dei_LegalEntityAxis = duk_DukeEnergyIndianaMember |
(2)us-gaap_AccrualForEnvironmentalLossContingenciesPayments / dei_LegalEntityAxis = duk_DukeEnergyIndianaMember |
(4)us-gaap_AccrualForEnvironmentalLossContingenciesPayments / dei_LegalEntityAxis = duk_DukeEnergyIndianaMember |
Ending balance |
$ 10us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyIndianaMember |
$ 7us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyIndianaMember |
$ 8us-gaap_AccrualForEnvironmentalLossContingencies / dei_LegalEntityAxis = duk_DukeEnergyIndianaMember |