Debt and Credit Facilities (Annual Maturities) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	$ 3,141	$ 3,406
Long-term Debt, Fiscal Year Maturity [Abstract]
2020	3,141
2021	5,053
2022	4,334
2023	3,112
2024	1,965
Thereafter	39,542
Total long-term debt, including current maturities	57,147
Purchase accounting adjustments	(1,500)	(1,600)
Other
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	361
Purchase Accounting Adjustments
Long-term Debt, Fiscal Year Maturity [Abstract]
Purchase accounting adjustments	$ 1,448
Parent Company \| Debt Maturing June 2020, 2.100% Coupon \| Unsecured Debt
Current Maturities Of Long Term Debt [Abstract]
Interest rate	2.10%
Current maturities of long-term debt	$ 330
Duke Energy Carolinas
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	458	6
Long-term Debt, Fiscal Year Maturity [Abstract]
2020	458
2021	504
2022	830
2023	1,006
2024	306
Thereafter	8,875
Total long-term debt, including current maturities	$ 11,979
Duke Energy Carolinas \| Bonds Maturing June 2020, 4.300% Coupon \| First Mortgage
Current Maturities Of Long Term Debt [Abstract]
Interest rate	4.30%
Current maturities of long-term debt	$ 450
Progress Energy
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	1,577	1,672
Long-term Debt, Fiscal Year Maturity [Abstract]
2020	1,578
2021	2,257
2022	1,048
2023	398
2024	227
Thereafter	14,267
Total long-term debt, including current maturities	19,775
Duke Energy Progress
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	1,006	603
Long-term Debt, Fiscal Year Maturity [Abstract]
2020	1,006
2021	932
2022	508
2023	319
2024	160
Thereafter	6,190
Total long-term debt, including current maturities	$ 9,115
Duke Energy Progress \| Bonds Maturing September 2020, 2.282% Coupon \| First Mortgage
Current Maturities Of Long Term Debt [Abstract]
Interest rate	2.065%
Current maturities of long-term debt	$ 300
Duke Energy Progress \| Parent Company \| Debt Maturing December 2020, 2.510% Coupon \| Unsecured Debt
Current Maturities Of Long Term Debt [Abstract]
Interest rate	2.51%
Current maturities of long-term debt	$ 700
Duke Energy Florida
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	571	270
Long-term Debt, Fiscal Year Maturity [Abstract]
2020	572
2021	825
2022	90
2023	79
2024	67
Thereafter	6,427
Total long-term debt, including current maturities	$ 8,060
Duke Energy Florida \| Bonds Maturing January 2019, 5.300% Coupon \| First Mortgage
Current Maturities Of Long Term Debt [Abstract]
Interest rate	1.85%
Current maturities of long-term debt	$ 250
Duke Energy Florida \| Bonds Maturing April 2019, 5.450% Coupon \| First Mortgage
Current Maturities Of Long Term Debt [Abstract]
Interest rate	4.55%
Current maturities of long-term debt	$ 250
Duke Energy Ohio
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt		551
Long-term Debt, Fiscal Year Maturity [Abstract]
2020	0
2021	50
2022	0
2023	325
2024	25
Thereafter	2,261
Total long-term debt, including current maturities	2,661
Duke Energy Indiana
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt	503	63
Long-term Debt, Fiscal Year Maturity [Abstract]
2020	503
2021	70
2022	94
2023	3
2024	154
Thereafter	3,272
Total long-term debt, including current maturities	$ 4,096
Duke Energy Indiana \| Bonds Maturing July 2020, 3.750% Coupon \| First Mortgage
Current Maturities Of Long Term Debt [Abstract]
Interest rate	3.75%
Current maturities of long-term debt	$ 500
Piedmont
Current Maturities Of Long Term Debt [Abstract]
Current maturities of long-term debt		$ 350
Long-term Debt, Fiscal Year Maturity [Abstract]
2020	0
2021	160
2022	0
2023	45
2024	40
Thereafter	2,155
Total long-term debt, including current maturities	$ 2,400

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

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

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

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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.

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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.

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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.

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