XML 127 R85.htm IDEA: XBRL DOCUMENT
v3.19.2

Fair Value Measurements (Fair Value Measurement Amounts for Assets and Liabilities) (Details) - USD ($) $ in Millions | Jun. 30, 2019 | Dec. 31, 2018
--- | --- | ---
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Debt securities, available-for-sale | $ 2,577 |
Derivative assets | 38 | $ 57
Total assets | 8,068 | 7,132
Derivative liabilities | (342) | (242)
Net assets (liabilities) | 7,726 | 6,890
Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative assets | 3 | 4
Total assets | 6,203 | 5,156
Derivative liabilities | (12) | (11)
Net assets (liabilities) | 6,191 | 5,145
Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative assets |  | 25
Total assets | 1,771 | 1,883
Derivative liabilities | (216) | (90)
Net assets (liabilities) | 1,555 | 1,793
Level 3 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative assets | 35 | 28
Total assets | 35 | 28
Derivative liabilities | (114) | (141)
Net assets (liabilities) | (79) | (113)
Fair Value Measured at Net Asset Value Per Share [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total assets | 59 | 65
Net assets (liabilities) | 59 | 65
Ndtf [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Equity securities, FV-NI | 5,178 | 4,475
Debt securities, available-for-sale | 2,425 | 2,231
Ndtf [Member] | Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Equity securities, FV-NI | 5,119 | 4,410
Debt securities, available-for-sale | 870 | 576
Ndtf [Member] | Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Debt securities, available-for-sale | 1,555 | 1,655
Ndtf [Member] | Fair Value Measured at Net Asset Value Per Share [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Equity securities, FV-NI | 59 | 65
Other Classification [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Equity securities, FV-NI | 112 | 99
Debt securities, available-for-sale | 315 | 270
Other Classification [Member] | Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Equity securities, FV-NI | 112 | 99
Debt securities, available-for-sale | 99 | 67
Other Classification [Member] | Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Debt securities, available-for-sale | 216 | 203
Duke Energy Carolinas [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Debt securities, available-for-sale | 1,120 |
Derivative assets |  | 3
Total assets | 4,044 | 3,556
Derivative liabilities | (93) | (33)
Net assets (liabilities) | 3,951 | 3,523
Duke Energy Carolinas [Member] | Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total assets | 3,074 | 2,568
Net assets (liabilities) | 3,074 | 2,568
Duke Energy Carolinas [Member] | Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative assets |  | 3
Total assets | 911 | 923
Derivative liabilities | (93) | (33)
Net assets (liabilities) | 818 | 890
Duke Energy Carolinas [Member] | Fair Value Measured at Net Asset Value Per Share [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total assets | 59 | 65
Net assets (liabilities) | 59 | 65
Duke Energy Carolinas [Member] | Ndtf [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Equity securities, FV-NI | 2,883 | 2,484
Debt securities, available-for-sale | 1,161 | 1,069
Duke Energy Carolinas [Member] | Ndtf [Member] | Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Equity securities, FV-NI | 2,824 | 2,419
Debt securities, available-for-sale | 250 | 149
Duke Energy Carolinas [Member] | Ndtf [Member] | Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Debt securities, available-for-sale | 911 | 920
Duke Energy Carolinas [Member] | Ndtf [Member] | Fair Value Measured at Net Asset Value Per Share [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Equity securities, FV-NI | 59 | 65
Progress Energy [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Debt securities, available-for-sale | 1,241 |
Derivative assets |  | 4
Total assets | 3,656 | 3,221
Derivative liabilities | (90) | (44)
Net assets (liabilities) | 3,566 | 3,177
Progress Energy [Member] | Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total assets | 2,962 | 2,435
Net assets (liabilities) | 2,962 | 2,435
Progress Energy [Member] | Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative assets | 0 | 4
Total assets | 694 | 786
Derivative liabilities | (90) | (44)
Net assets (liabilities) | 604 | 742
Progress Energy [Member] | Ndtf [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Equity securities, FV-NI | 2,295 | 1,991
Debt securities, available-for-sale | 1,264 | 1,162
Progress Energy [Member] | Ndtf [Member] | Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Equity securities, FV-NI | 2,295 | 1,991
Debt securities, available-for-sale | 620 | 427
Progress Energy [Member] | Ndtf [Member] | Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Debt securities, available-for-sale | 644 | 735
Progress Energy [Member] | Other Classification [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Debt securities, available-for-sale | 97 | 64
Progress Energy [Member] | Other Classification [Member] | Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Debt securities, available-for-sale | 47 | 17
Progress Energy [Member] | Other Classification [Member] | Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Debt securities, available-for-sale | 50 | 47
Duke Energy Progress [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Debt securities, available-for-sale | 906 |
Derivative assets |  | 4
Total assets | 2,836 | 2,504
Derivative liabilities | (35) | (27)
Net assets (liabilities) | 2,801 | 2,477
Duke Energy Progress [Member] | Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total assets | 2,192 | 1,888
Net assets (liabilities) | 2,192 | 1,888
Duke Energy Progress [Member] | Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative assets |  | 4
Total assets | 644 | 616
Derivative liabilities | (35) | (27)
Net assets (liabilities) | 609 | 589
Duke Energy Progress [Member] | Ndtf [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Equity securities, FV-NI | 1,886 | 1,588
Debt securities, available-for-sale | 948 | 906
Duke Energy Progress [Member] | Ndtf [Member] | Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Equity securities, FV-NI | 1,886 | 1,588
Debt securities, available-for-sale | 304 | 294
Duke Energy Progress [Member] | Ndtf [Member] | Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Debt securities, available-for-sale | 644 | 612
Duke Energy Progress [Member] | Other Classification [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Debt securities, available-for-sale | 2 | 6
Duke Energy Progress [Member] | Other Classification [Member] | Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Debt securities, available-for-sale | 2 | 6
Duke Energy Florida [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Debt securities, available-for-sale | 335 |
Total assets | 777 | 707
Derivative liabilities | (39) | (9)
Net assets (liabilities) | 738 | 698
Duke Energy Florida [Member] | Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total assets | 727 | 537
Net assets (liabilities) | 727 | 537
Duke Energy Florida [Member] | Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total assets | 50 | 170
Derivative liabilities | (39) | (9)
Net assets (liabilities) | 11 | 161
Duke Energy Florida [Member] | Ndtf [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Equity securities, FV-NI | 409 | 403
Debt securities, available-for-sale | 316 | 256
Duke Energy Florida [Member] | Ndtf [Member] | Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Equity securities, FV-NI | 409 | 403
Debt securities, available-for-sale | 316 | 133
Duke Energy Florida [Member] | Ndtf [Member] | Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Debt securities, available-for-sale |  | 123
Duke Energy Florida [Member] | Other Classification [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Debt securities, available-for-sale | 52 | 48
Duke Energy Florida [Member] | Other Classification [Member] | Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Debt securities, available-for-sale | 2 | 1
Duke Energy Florida [Member] | Other Classification [Member] | Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Debt securities, available-for-sale | 50 | 47
Duke Energy Indiana [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Equity securities, FV-NI | 74 | 67
Debt securities, available-for-sale | 42 |
Derivative assets | 29 | 23
Total assets | 145 | 131
Derivative liabilities | (2) |
Net assets (liabilities) | 143 | 131
Duke Energy Indiana [Member] | Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative assets | 1 | 1
Total assets | 75 | 68
Derivative liabilities | (2) |
Net assets (liabilities) | 73 | 68
Duke Energy Indiana [Member] | Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Total assets | 42 | 41
Net assets (liabilities) | 42 | 41
Duke Energy Indiana [Member] | Level 3 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative assets | 28 | 22
Total assets | 28 | 22
Net assets (liabilities) | 28 | 22
Duke Energy Indiana [Member] | Other Classification [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Equity securities, FV-NI | 74 | 67
Duke Energy Indiana [Member] | Other Classification [Member] | Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Equity securities, FV-NI | 74 | 67
Piedmont Natural Gas [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative assets | 2 | 3
Derivative liabilities | (114) | (141)
Net assets (liabilities) | (112) | (138)
Piedmont Natural Gas [Member] | Level 1 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative assets | 2 | 3
Net assets (liabilities) | 2 | 3
Piedmont Natural Gas [Member] | Level 3 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Derivative liabilities | (114) | (141)
Net assets (liabilities) | (114) | (141)
Debt Securities [Member] | Duke Energy Indiana [Member] | Other Classification [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Debt securities, available-for-sale | 42 | 41
Debt Securities [Member] | Duke Energy Indiana [Member] | Other Classification [Member] | Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Debt securities, available-for-sale | $ 42 | $ 41

X
- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=118942338&loc=SL82898722-210454 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118954083&loc=d3e26610-111562 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13433-108611 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 + Details
Name: | us-gaap_DerivativeAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13433-108611 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313 + Details
Name: | us-gaap_DerivativeLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=99377092&loc=SL75136599-209740 + Details
Name: | us-gaap_EquitySecuritiesFvNi
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value of asset after deduction of liability. + References No definition available. + Details
Name: | us-gaap_FairValueNetAssetLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentSecondaryCategorizationAxis=duk_NdtfMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentSecondaryCategorizationAxis=duk_OtherClassificationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=duk_DukeEnergyCarolinasMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=duk_ProgressEnergyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=duk_DukeEnergyProgressMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=duk_DukeEnergyFloridaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=duk_DukeEnergyIndianaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=duk_PiedmontNaturalGasMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_DebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |