Anticipated future borrowings under the credit facility.

No definition available.

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Namespace Prefix:	duk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Period of time in which remaining available borrowings may be drawn on a line of credit facility.

+ References

No definition available.

+ Details

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Namespace Prefix:	duk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Remaining number of borrowings available to draw on a line of credit facility.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Minimum Master Credit Facility Balance Required to be maintained to meet obligations outlined in Plea Agreements

+ References

No definition available.

+ Details

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Namespace Prefix:	duk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- 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

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ 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(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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Balance Type:
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- Details

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- Details

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Balance Type:
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- Details

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Debt and Credit Facilities (Narrative) (Details)	3 Months Ended	6 Months Ended
Debt and Credit Facilities (Narrative) (Details)	Jun. 30, 2017 USD ($) Integer	Jun. 30, 2017 USD ($) Integer	Dec. 31, 2016 USD ($)
Debt Instrument [Line Items]
Debt issuances	$ 2,337,000,000	$ 2,337,000,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility size	8,000,000,000	8,000,000,000	$ 7,500,000,000.0
Line of Credit Facility, Remaining Borrowing Capacity	4,236,000,000	4,236,000,000
Parent Company [Member]
Debt Instrument [Line Items]
Debt issuances	750,000,000	750,000,000
Parent Company [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility size	3,150,000,000	3,150,000,000
Line of Credit Facility, Remaining Borrowing Capacity	1,699,000,000	1,699,000,000
Parent Company [Member] \| June 2017 Three Year Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility size	1,000,000,000	1,000,000,000
Long-term Line of Credit	270,000,000	$ 270,000,000
Debt Instrument, Term		3 years
Piedmont Natural Gas [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility size	500,000,000	$ 500,000,000	$ 850,000,000
Line of Credit Facility, Remaining Borrowing Capacity	363,000,000	363,000,000
Piedmont Natural Gas [Member] \| June 2017 Piedmont Term Loan Facility [Member]
Debt Instrument [Line Items]
Facility size	250,000,000	250,000,000
Long-term Line of Credit	125,000,000	125,000,000
Line of Credit Facility, Remaining Borrowing Capacity	$ 125,000,000	$ 125,000,000
Line Of Credit Facility, Remaining Available Borrowings \| Integer	1	1
Line Of Credit Facility, Remaining Available Borrowing Period		90 days
Debt Instrument, Term		18 months
Line Of Credit Facility, Expected Borrowings	$ 125,000,000	$ 125,000,000
Duke Energy Carolinas [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility size	1,350,000,000	1,350,000,000
Line of Credit Facility, Remaining Borrowing Capacity	364,000,000	364,000,000
Duke Energy Carolinas [Member] \| USDOJ [Member] \| North Carolina Ash Basins [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Minimum Master Credit Facility Balance Required	250,000,000	250,000,000
Duke Energy Progress [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility size	1,250,000,000	1,250,000,000
Line of Credit Facility, Remaining Borrowing Capacity	337,000,000	337,000,000
Duke Energy Progress [Member] \| USDOJ [Member] \| North Carolina Ash Basins [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Minimum Master Credit Facility Balance Required	250,000,000	250,000,000
April 2017 Debt Issuance, 3.364% Coupon [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuances	$ 420,000,000	$ 420,000,000
Interest rate	3.364%	3.364%
April 2017 Debt Issuance, 3.364% Coupon [Member] \| Parent Company [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuances	$ 420,000,000	$ 420,000,000
Interest rate	3.364%	3.364%
April 2017 Maturity [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Repayments of Debt	$ 400,000,000
April 2017 Maturity [Member] \| Parent Company [Member] \| Unsecured Debt [Member]
Debt Instrument [Line Items]
Repayments of Debt	$ 400,000,000