Debt and Credit Facilities (Annual Maturities) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	$ 2,319	$ 2,026
Long-term Debt, Fiscal Year Maturity [Abstract]
2017	2,319
2018	3,466
2019	3,316
2020	2,112
2021	3,699
Thereafter	31,090
Total long-term debt, including current maturities	46,002
Other Debt Obligations [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	$ 293
June 2017 Maturity [Member] \| Secured Debt [Member]
Current Maturities Of Long Term Debt [Abstract]
Interest rate	2.365%
Current maturities of long-term debt	$ 45
June 2017 Maturity 2 [Member] \| Secured Debt [Member]
Current Maturities Of Long Term Debt [Abstract]
Interest rate	2.26%
Current maturities of long-term debt	$ 34
Purchase Accounting Adjustments [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
Purchase accounting adjustments	$ (1,893)
Parent Company [Member] \| April 2017 Debt Maturity [Member] \| Unsecured Debt [Member]
Current Maturities Of Long Term Debt [Abstract]
Interest rate	1.226%
Current maturities of long-term debt	$ 400
Parent Company [Member] \| August 2017 Debt Maturity [Member] \| Unsecured Debt [Member]
Current Maturities Of Long Term Debt [Abstract]
Interest rate	1.625%
Current maturities of long-term debt	$ 700
Piedmont Natural Gas [Member] \| September 2017 Debt Maturity [Member] \| Unsecured Debt [Member]
Current Maturities Of Long Term Debt [Abstract]
Interest rate	8.51%
Current maturities of long-term debt	$ 35
Duke Energy Carolinas [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	116	356
Long-term Debt, Fiscal Year Maturity [Abstract]
2017	116
2018	1,629
2019	5
2020	755
2021	501
Thereafter	6,597
Total long-term debt, including current maturities	$ 9,603
Duke Energy Carolinas [Member] \| February 2017 Debt Maturity [Member] \| Tax Exempt Bonds [Member]
Current Maturities Of Long Term Debt [Abstract]
Interest rate	3.60%
Current maturities of long-term debt	$ 77
Duke Energy Carolinas [Member] \| February 2017 Debt Maturity 2 [Member] \| Tax Exempt Bonds [Member]
Current Maturities Of Long Term Debt [Abstract]
Interest rate	0.81%
Current maturities of long-term debt	$ 10
Duke Energy Carolinas [Member] \| February 2017 Debt Maturity 3 [Member] \| Tax Exempt Bonds [Member]
Current Maturities Of Long Term Debt [Abstract]
Interest rate	0.79%
Current maturities of long-term debt	$ 25
Progress Energy [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	778	315
Long-term Debt, Fiscal Year Maturity [Abstract]
2017	778
2018	559
2019	1,992
2020	469
2021	1,473
Thereafter	12,270
Total long-term debt, including current maturities	17,541
Duke Energy Progress [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	452	2
Long-term Debt, Fiscal Year Maturity [Abstract]
2017	452
2018	0
2019	902
2020	152
2021	602
Thereafter	4,903
Total long-term debt, including current maturities	$ 7,011
Duke Energy Progress [Member] \| March 2017 Debt Maturity [Member] \| First Mortgage Bonds [Member]
Current Maturities Of Long Term Debt [Abstract]
Interest rate	1.146%
Current maturities of long-term debt	$ 250
Duke Energy Progress [Member] \| November 2017 Debt Maturity [Member] \| First Mortgage Bonds [Member]
Current Maturities Of Long Term Debt [Abstract]
Interest rate	1.111%
Current maturities of long-term debt	$ 200
Duke Energy Florida [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	326	13
Long-term Debt, Fiscal Year Maturity [Abstract]
2017	326
2018	561
2019	292
2020	319
2021	372
Thereafter	4,255
Total long-term debt, including current maturities	$ 6,125
Duke Energy Florida [Member] \| September 2017 Debt Maturity [Member] \| First Mortgage Bonds [Member]
Current Maturities Of Long Term Debt [Abstract]
Interest rate	5.80%
Current maturities of long-term debt	$ 250
Duke Energy Ohio [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	1	106
Long-term Debt, Fiscal Year Maturity [Abstract]
2017	1
2018	3
2019	551
2020	25
2021	49
Thereafter	1,255
Total long-term debt, including current maturities	1,884
Duke Energy Indiana [Member]
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	3	$ 547
Long-term Debt, Fiscal Year Maturity [Abstract]
2017	3
2018	3
2019	63
2020	653
2021	70
Thereafter	2,994
Total long-term debt, including current maturities	$ 3,786

Current Maturities of Long Term Debt

No definition available.

Name:	duk_CurrentMaturitiesOfLongTermDebtAbstract
Namespace Prefix:	duk_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Including current and noncurrent portions, aggregate carrying amount of long-term borrowings as of the balance sheet date, excluding purchase accounting adjustments.

+ References

No definition available.

+ Details

Name:	duk_LongTermDebtExcludingPurchaseAccountingAdjustments
Namespace Prefix:	duk_
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

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of unamortized debt discount (premium) and debt issuance costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28555-108399

+ Details

Name:	us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

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

- 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

+ Details

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

- Definition

Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04.(a))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690

+ Details

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

- Definition

Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04.(a))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601

+ Details

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

- Definition

Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

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

- Definition

Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

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

- Definition

Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

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

- Definition

Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

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