Debt and Credit Facilities (Summary of Debt Issuances) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Debt issuances	$ 6,210,000,000	$ 5,050,000,000
Redemption of long-term debt	$ 3,476,000,000	$ 2,906,000,000	$ 2,316,000,000
March 2019 Debt Issuance Due March 2022 | Unsecured Debt
Debt Instrument [Line Items]
Interest rate	2.538%
Debt issuances	$ 300,000,000
March 2019 Debt Issuance 3.227% Coupon Due 2022 | Unsecured Debt
Debt Instrument [Line Items]
Interest rate	3.227%
Debt issuances	$ 300,000,000
May 2019 Debt Issuance 3.500% Coupon Due 2029 | Unsecured Debt
Debt Instrument [Line Items]
Interest rate	3.50%
Debt issuances	$ 600,000,000
June 2019 Debt Issuance 3.400% Coupon Due 2029 | Unsecured Debt
Debt Instrument [Line Items]
Interest rate	3.40%
Debt issuances	$ 600,000,000
June 2019 Debt Issuance 4.200% Coupon Due 2049 | Unsecured Debt
Debt Instrument [Line Items]
Interest rate	4.20%
Debt issuances	$ 600,000,000
July 2019 Debt Issuance 4.320% Coupon Due 2049 | Unsecured Debt
Debt Instrument [Line Items]
Interest rate	4.32%
Debt issuances	$ 40,000,000
September 2019 Debt Issuance 3.230% Coupon Due 2025 | Unsecured Debt
Debt Instrument [Line Items]
Interest rate	3.23%
Debt issuances	$ 95,000,000
September 2019 Debt Issuance 3.560% Coupon Due 2029 | Unsecured Debt
Debt Instrument [Line Items]
Interest rate	3.56%
Debt issuances	$ 75,000,000
November 2019 Debt Issuance 2.167% Coupon Due 2021 | Unsecured Debt
Debt Instrument [Line Items]
Interest rate	2.167%
Debt issuances	$ 200,000,000
January 2019 Debt Issuance 3.650% Coupon Due 2029 | First Mortgage
Debt Instrument [Line Items]
Interest rate	3.65%
Debt issuances	$ 400,000,000
January 2019 Debt Issuance 4.300% Coupon Due 2049 | First Mortgage
Debt Instrument [Line Items]
Interest rate	4.30%
Debt issuances	$ 400,000,000
March 2019 Debt Issuance 3.450% Coupon Due 2029 | First Mortgage
Debt Instrument [Line Items]
Interest rate	3.45%
Debt issuances	$ 600,000,000
August 2019 Debt Issuance 2.450% Coupon Due 2029 | First Mortgage
Debt Instrument [Line Items]
Interest rate	2.45%
Debt issuances	$ 450,000,000
August 2019 Debt Issuance 3.200% Coupon Due 2049 | First Mortgage
Debt Instrument [Line Items]
Interest rate	3.20%
Debt issuances	$ 350,000,000
September 2019 Debt Issuance 3.250% Coupon Due 2049 | First Mortgage
Debt Instrument [Line Items]
Interest rate	3.25%
Debt issuances	$ 500,000,000
November 2019 Debt Issuance 2.500% Coupon Due 2029
Debt Instrument [Line Items]
Interest rate	2.50%
November 2019 Debt Issuance 2.500% Coupon Due 2029 | First Mortgage
Debt Instrument [Line Items]
Debt issuances	$ 700,000,000
March 2018 Debt Issuance 3.950% Coupon Due 2025
Debt Instrument [Line Items]
Interest rate		3.95%
March 2018 Debt Issuance 3.950% Coupon Due 2025 | Unsecured Debt
Debt Instrument [Line Items]
Debt issuances		$ 250,000,000
May 2018 Debt Issuance 3.114% Coupon Due 2021
Debt Instrument [Line Items]
Interest rate		3.114%
May 2018 Debt Issuance 3.114% Coupon Due 2021 | Unsecured Debt
Debt Instrument [Line Items]
Debt issuances		$ 500,000,000
September 2018 Debt Issuance 5.625% Coupon Due 2078
Debt Instrument [Line Items]
Interest rate		5.625%
September 2018 Debt Issuance 5.625% Coupon Due 2078 | Unsecured Debt
Debt Instrument [Line Items]
Debt issuances		$ 500,000,000
March 2018 Debt Issuance 3.050% Coupon Due 2023
Debt Instrument [Line Items]
Interest rate		3.05%
March 2018 Debt Issuance 3.050% Coupon Due 2023 | First Mortgage
Debt Instrument [Line Items]
Debt issuances		$ 500,000,000
March 2018 Debt Issuance 3.950% Coupon Due 2048
Debt Instrument [Line Items]
Interest rate		3.95%
March 2018 Debt Issuance 3.950% Coupon Due 2048 | First Mortgage
Debt Instrument [Line Items]
Debt issuances		$ 500,000,000
June 2018 Debt issuance 3.80% coupon Due 2028
Debt Instrument [Line Items]
Interest rate		3.80%
June 2018 Debt issuance 3.80% coupon Due 2028 | First Mortgage
Debt Instrument [Line Items]
Debt issuances		$ 600,000,000
June 2018 Debt Issuance 4.20 Coupon Due 2048
Debt Instrument [Line Items]
Interest rate		4.20%
June 2018 Debt Issuance 4.20 Coupon Due 2048 | First Mortgage
Debt Instrument [Line Items]
Debt issuances		$ 400,000,000
August 2018 Debt Issuance 3.375% Coupon Due 2023
Debt Instrument [Line Items]
Interest rate		3.375%
August 2018 Debt Issuance 3.375% Coupon Due 2023 | First Mortgage
Debt Instrument [Line Items]
Debt issuances		$ 300,000,000
August 2018 Debt Issuance 3.700% Coupon Due 2028
Debt Instrument [Line Items]
Interest rate		3.70%
August 2018 Debt Issuance 3.700% Coupon Due 2028 | First Mortgage
Debt Instrument [Line Items]
Debt issuances		$ 500,000,000
November 2018 Debt Issuance 3.350% Coupon Due 2022
Debt Instrument [Line Items]
Interest rate		3.35%
November 2018 Debt Issuance 3.350% Coupon Due 2022 | First Mortgage
Debt Instrument [Line Items]
Debt issuances		$ 350,000,000
November 2018 Debt Issuance 3.950% Coupon Due 2028
Debt Instrument [Line Items]
Interest rate		3.95%
November 2018 Debt Issuance 3.950% Coupon Due 2028 | First Mortgage
Debt Instrument [Line Items]
Debt issuances		$ 650,000,000
Parent Company
Debt Instrument [Line Items]
Debt issuances	1,800,000,000	1,250,000,000
Parent Company | March 2019 Debt Issuance Due March 2022 | Unsecured Debt
Debt Instrument [Line Items]
Debt issuances	300,000,000
Parent Company | March 2019 Debt Issuance 3.227% Coupon Due 2022 | Unsecured Debt
Debt Instrument [Line Items]
Debt issuances	300,000,000
Parent Company | June 2019 Debt Issuance 3.400% Coupon Due 2029 | Unsecured Debt
Debt Instrument [Line Items]
Debt issuances	600,000,000
Parent Company | June 2019 Debt Issuance 4.200% Coupon Due 2049 | Unsecured Debt
Debt Instrument [Line Items]
Debt issuances	600,000,000
Parent Company | March 2018 Debt Issuance 3.950% Coupon Due 2025 | Unsecured Debt
Debt Instrument [Line Items]
Debt issuances		250,000,000
Parent Company | May 2018 Debt Issuance 3.114% Coupon Due 2021 | Unsecured Debt
Debt Instrument [Line Items]
Debt issuances		500,000,000
Parent Company | September 2018 Debt Issuance 5.625% Coupon Due 2078 | Unsecured Debt
Debt Instrument [Line Items]
Debt issuances		500,000,000
Duke Energy Carolinas
Debt Instrument [Line Items]
Debt issuances	800,000,000	2,000,000,000
Redemption of long-term debt	6,000,000	1,205,000,000	116,000,000
Duke Energy Carolinas | First Mortgage
Debt Instrument [Line Items]
Debt issuances		350,000,000
Duke Energy Carolinas | August 2019 Debt Issuance 2.450% Coupon Due 2029 | First Mortgage
Debt Instrument [Line Items]
Debt issuances	450,000,000
Duke Energy Carolinas | August 2019 Debt Issuance 3.200% Coupon Due 2049 | First Mortgage
Debt Instrument [Line Items]
Debt issuances	350,000,000
Duke Energy Carolinas | March 2018 Debt Issuance 3.050% Coupon Due 2023 | First Mortgage
Debt Instrument [Line Items]
Debt issuances		500,000,000
Duke Energy Carolinas | March 2018 Debt Issuance 3.950% Coupon Due 2048 | First Mortgage
Debt Instrument [Line Items]
Debt issuances		500,000,000
Duke Energy Carolinas | November 2018 Debt Issuance 3.950% Coupon Due 2028 | First Mortgage
Debt Instrument [Line Items]
Debt issuances		650,000,000
Duke Energy Carolinas | First Mortgage Bonds Maturing April 2018, 5.100% Coupon
Debt Instrument [Line Items]
Repayments of debt		300,000,000
Duke Energy Progress
Debt Instrument [Line Items]
Debt issuances	600,000,000	800,000,000
Redemption of long-term debt	605,000,000	3,000,000	470,000,000
Duke Energy Progress | March 2019 Debt Issuance 3.450% Coupon Due 2029 | First Mortgage
Debt Instrument [Line Items]
Debt issuances	600,000,000
Duke Energy Progress | August 2018 Debt Issuance 3.375% Coupon Due 2023 | First Mortgage
Debt Instrument [Line Items]
Debt issuances		300,000,000
Duke Energy Progress | August 2018 Debt Issuance 3.700% Coupon Due 2028 | First Mortgage
Debt Instrument [Line Items]
Debt issuances		500,000,000
Duke Energy Florida
Debt Instrument [Line Items]
Debt issuances	900,000,000	1,000,000,000
Redemption of long-term debt	262,000,000	769,000,000	342,000,000
Duke Energy Florida | November 2019 Debt Issuance 2.167% Coupon Due 2021 | Unsecured Debt
Debt Instrument [Line Items]
Debt issuances	200,000,000
Duke Energy Florida | March 2019 Debt Issuance 3.450% Coupon Due 2029 | First Mortgage
Debt Instrument [Line Items]
Debt issuances	0
Duke Energy Florida | November 2019 Debt Issuance 2.500% Coupon Due 2029 | First Mortgage
Debt Instrument [Line Items]
Debt issuances	700,000,000
Duke Energy Florida | June 2018 Debt issuance 3.80% coupon Due 2028 | First Mortgage
Debt Instrument [Line Items]
Debt issuances		600,000,000
Duke Energy Florida | June 2018 Debt Issuance 4.20 Coupon Due 2048 | First Mortgage
Debt Instrument [Line Items]
Debt issuances		400,000,000
Duke Energy Ohio
Debt Instrument [Line Items]
Debt issuances	1,010,000,000
Redemption of long-term debt	551,000,000	3,000,000	2,000,000
Duke Energy Ohio | July 2019 Debt Issuance 4.320% Coupon Due 2049 | Unsecured Debt
Debt Instrument [Line Items]
Debt issuances	40,000,000
Duke Energy Ohio | September 2019 Debt Issuance 3.230% Coupon Due 2025 | Unsecured Debt
Debt Instrument [Line Items]
Debt issuances	95,000,000
Duke Energy Ohio | September 2019 Debt Issuance 3.560% Coupon Due 2029 | Unsecured Debt
Debt Instrument [Line Items]
Debt issuances	75,000,000
Duke Energy Ohio | January 2019 Debt Issuance 3.650% Coupon Due 2029 | First Mortgage
Debt Instrument [Line Items]
Debt issuances	400,000,000
Duke Energy Ohio | January 2019 Debt Issuance 4.300% Coupon Due 2049 | First Mortgage
Debt Instrument [Line Items]
Debt issuances	400,000,000
Duke Energy Ohio | April 2019 First Mortgage Bonds
Debt Instrument [Line Items]
Redemption of long-term debt	450,000,000
Duke Energy Ohio | Debentures Due October 2019
Debt Instrument [Line Items]
Redemption of long-term debt	100,000,000
Duke Energy Indiana
Debt Instrument [Line Items]
Debt issuances	500,000,000
Redemption of long-term debt	213,000,000	$ 3,000,000	5,000,000
Duke Energy Indiana | September 2019 Debt Issuance 3.250% Coupon Due 2049 | First Mortgage
Debt Instrument [Line Items]
Debt issuances	500,000,000
Duke Energy Indiana | Pollution Control Bonds
Debt Instrument [Line Items]
Redemption of long-term debt	150,000,000
Piedmont
Debt Instrument [Line Items]
Debt issuances	600,000,000
Redemption of long-term debt	350,000,000		$ 35,000,000
Piedmont | May 2019 Debt Issuance 3.500% Coupon Due 2029 | Unsecured Debt
Debt Instrument [Line Items]
Debt issuances	600,000,000
Piedmont | Senior Unsecured Term Loan Facility Due September 2019
Debt Instrument [Line Items]
Redemption of long-term debt	$ 350,000,000