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

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

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(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

Amount of cash distribution paid to unit-holder of limited liability company (LLC).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055

+ Details

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

- 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

Debt and Credit Facilities (Summary of Debt Issuances) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Jun. 30, 2015
Debt Instrument [Line Items]
Debt issuances		$ 3,394
Parent Company [Member]
Debt Instrument [Line Items]
Debt issuances		350
Duke Energy Carolinas [Member]
Debt Instrument [Line Items]
Debt issuances		1,000
Distributions to parent		1,200	$ 100
Duke Energy Florida [Member]
Debt Instrument [Line Items]
Debt issuances		1,294
Distributions to parent		649
Duke Energy Ohio [Member]
Debt Instrument [Line Items]
Debt issuances		250
Duke Energy Indiana [Member]
Debt Instrument [Line Items]
Debt issuances		500
Distributions to parent		149
Unsecured Debt [Member] \| April 2016 2.875% Unsecured Note Maturing April 2023 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 350
Interest rate		2.875%
Unsecured Debt [Member] \| Parent Company [Member] \| April 2016 2.875% Unsecured Note Maturing April 2023 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 350
Interest rate		2.875%
First Mortgage [Member] \| March 2016 2.500% First Mortgage Bond Maturing March 2023 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 500
Interest rate		2.50%
First Mortgage [Member] \| March 2016 3.875% First Mortgage Bond Maturing March 2046 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 500
Interest rate		3.875%
First Mortgage [Member] \| May 2016 3.750% First Mortgage Bond Maturing May 2046 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 500
Interest rate		3.75%
Repayments of Debt		$ 325
First Mortgage [Member] \| June 2016 3.700% First Mortgage Bond Maturing June 2046 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 250
Interest rate		3.70%
First Mortgage [Member] \| Duke Energy Carolinas [Member] \| March 2016 2.500% First Mortgage Bond Maturing March 2023 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 500
Interest rate		2.50%
First Mortgage [Member] \| Duke Energy Carolinas [Member] \| March 2016 3.875% First Mortgage Bond Maturing March 2046 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 500
Interest rate		3.875%
First Mortgage [Member] \| Duke Energy Ohio [Member] \| June 2016 3.700% First Mortgage Bond Maturing June 2046 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 250
Interest rate		3.70%
First Mortgage [Member] \| Duke Energy Indiana [Member] \| May 2016 3.750% First Mortgage Bond Maturing May 2046 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 500
Interest rate		3.75%
Repayments of Debt		$ 325
Secured Debt [Member] \| June 2016 1.196% Secured Debt Maturing March 2020 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 183
Interest rate		1.196%
Secured Debt [Member] \| June 2016 1.731% Secured Debt Maturing September 2022 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 150
Interest rate		1.731%
Secured Debt [Member] \| June 2016 2.538% Secured Debt Maturing September 2029 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 436
Interest rate		2.538%
Secured Debt [Member] \| June 2016 2.858% Secured Debt Maturing March 2033 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 250
Interest rate		2.858%
Secured Debt [Member] \| June 2016 3.112% Secured Debt Maturing September 2036 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 275
Interest rate		3.112%
Secured Debt [Member] \| Duke Energy Florida [Member] \| June 2016 1.196% Secured Debt Maturing March 2020 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 183
Interest rate		1.196%
Distributions to parent		$ 649
Secured Debt [Member] \| Duke Energy Florida [Member] \| June 2016 1.731% Secured Debt Maturing September 2022 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 150
Interest rate		1.731%
Distributions to parent		$ 649
Secured Debt [Member] \| Duke Energy Florida [Member] \| June 2016 2.538% Secured Debt Maturing September 2029 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 436
Interest rate		2.538%
Distributions to parent		$ 649
Secured Debt [Member] \| Duke Energy Florida [Member] \| June 2016 2.858% Secured Debt Maturing March 2033 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 250
Interest rate		2.858%
Distributions to parent		$ 649
Secured Debt [Member] \| Duke Energy Florida [Member] \| June 2016 3.112% Secured Debt Maturing September 2036 [Member]
Debt Instrument [Line Items]
Debt issuances		$ 275
Interest rate		3.112%
Distributions to parent		$ 649
Subsequent Event [Member] \| First Mortgage [Member] \| May 2016 3.750% First Mortgage Bond Maturing May 2046 [Member]
Debt Instrument [Line Items]
Repayments of Debt	$ 150
Subsequent Event [Member] \| First Mortgage [Member] \| Duke Energy Indiana [Member] \| May 2016 3.750% First Mortgage Bond Maturing May 2046 [Member]
Debt Instrument [Line Items]
Repayments of Debt	$ 150