Debt and Credit Facilities (Summary of Current Maturities of Long-term Debt)(Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 1,977	$ 2,319
Secured Debt [Member] \| Secured Debt Maturing June 2017, 2.605% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	2.605%
Current maturities of long-term debt	$ 45
Secured Debt [Member] \| Secured Debt Maturing June 2017, 2.455% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	2.455%
Current maturities of long-term debt	$ 34
Other Debt Obligations [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 313
Parent Company [Member] \| Unsecured Debt [Member] \| Unsecured Debt Maturing August 2017, 1.625% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	1.625%
Current maturities of long-term debt	$ 700
Duke Energy Carolinas [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 404	116
Duke Energy Carolinas [Member] \| First Mortgage Bonds [Member] \| First Mortgage Bonds Maturing January 2018, 5.250% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	5.25%
Current maturities of long-term debt	$ 400
Duke Energy Progress [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 202	452
Duke Energy Progress [Member] \| First Mortgage Bonds [Member] \| First Mortgage Bonds Maturing November 2017, 1.252% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	1.252%
Current maturities of long-term debt	$ 200
Duke Energy Florida [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 319	326
Duke Energy Florida [Member] \| First Mortgage Bonds [Member] \| First Mortgage Bonds Maturing September 2017, 5.800% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	5.80%
Current maturities of long-term debt	$ 250
Duke Energy Ohio [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	1	1
Duke Energy Indiana [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	3	3
Piedmont Natural Gas [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 35	$ 35
Piedmont Natural Gas [Member] \| Unsecured Debt [Member] \| Unsecured Debt Maturing September 2017, 8.510% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	8.51%
Current maturities of long-term debt	$ 35

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

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

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- 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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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ 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 210.5-02.19,20)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Balance Type:	credit
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