Debt and Credit Facilities (Summary of Debt Issuances) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Debt issuances	$ 5,050,000,000	$ 6,070,000,000
January 2017 Issuance Maturing January 2027 [Member]
Debt Instrument [Line Items]
Interest rate		3.20%
January 2017 Issuance Maturing January 2027 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances		$ 650,000,000
April 2017 Issuance Maturing April 2025 [Member]
Debt Instrument [Line Items]
Interest rate		3.364%
April 2017 Issuance Maturing April 2025 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuances		$ 420,000,000
June 2017 Issuance Maturing June 2020 [Member]
Debt Instrument [Line Items]
Interest rate		2.10%
June 2017 Issuance Maturing June 2020 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuances		$ 330,000,000
August 2017 Issuance Maturing August 2022 [Member]
Debt Instrument [Line Items]
Interest rate		2.40%
August 2017 Issuance Maturing August 2022 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuances		$ 500,000,000
August 2017 Issuance Maturing August 2027 [Member]
Debt Instrument [Line Items]
Interest rate		3.15%
August 2017 Issuance Maturing August 2027 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuances		$ 750,000,000
August 2017 Issuance Maturing August 2047 [Member]
Debt Instrument [Line Items]
Interest rate		3.95%
August 2017 Issuance Maturing August 2047 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuances		$ 500,000,000
December 2017 Issuance Maturing December 2019 [Member]
Debt Instrument [Line Items]
Interest rate		2.10%
December 2017 Issuance Maturing December 2019 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuances		$ 400,000,000
February 2017 Issuance Maturing June 2034 [Member]
Debt Instrument [Line Items]
Interest rate		4.12%
February 2017 Issuance Maturing June 2034 [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Debt issuances		$ 587,000,000
March 2018 Debt Issuance 3.950% Coupon Due 2025 [Member]
Debt Instrument [Line Items]
Interest rate	3.95%
March 2018 Debt Issuance 3.950% Coupon Due 2025 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuances	$ 250,000,000
May 2018 Debt Issuance 2.819% Coupon Due 2021 [Member]
Debt Instrument [Line Items]
Interest rate	3.114%
May 2018 Debt Issuance 2.819% Coupon Due 2021 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuances	$ 500,000,000
September 2018 Debt Issuance 5.625% Coupon Due 2078 [Member]
Debt Instrument [Line Items]
Interest rate	5.625%
September 2018 Debt Issuance 5.625% Coupon Due 2078 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuances	$ 500,000,000
June 2018 Debt Issuance 4.20 Coupon Due 2048 [Member]
Debt Instrument [Line Items]
Interest rate	4.20%
June 2018 Debt Issuance 4.20 Coupon Due 2048 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances	$ 400,000,000
August 2018 Debt Issuance 3.375% Coupon Due 2023 [Member]
Debt Instrument [Line Items]
Interest rate	3.375%
August 2018 Debt Issuance 3.375% Coupon Due 2023 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances	$ 300,000,000
August 2018 Debt Issuance 3.700% Coupon Due 2028 [Member]
Debt Instrument [Line Items]
Interest rate	3.70%
August 2018 Debt Issuance 3.700% Coupon Due 2028 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances	$ 500,000,000
November 2018 Debt Issuance 3.350% Coupon Due 2022 [Member]
Debt Instrument [Line Items]
Interest rate	3.35%
November 2018 Debt Issuance 3.350% Coupon Due 2022 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances	$ 350,000,000
August 2017 Issuance Maturing December 2036 [Member]
Debt Instrument [Line Items]
Interest rate		4.11%
August 2017 Issuance Maturing December 2036 [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Debt issuances		$ 233,000,000
March 2018 Debt Issuance 3.050% Coupon Due 2023 [Member]
Debt Instrument [Line Items]
Interest rate	3.05%
March 2018 Debt Issuance 3.050% Coupon Due 2023 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances	$ 500,000,000
March 2018 Debt Issuance 3.950% Coupon Due 2048 [Member]
Debt Instrument [Line Items]
Interest rate	3.95%
March 2018 Debt Issuance 3.950% Coupon Due 2048 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances	$ 500,000,000
June 2018 Debt issuance 3.80% coupon Due 2028 [Member]
Debt Instrument [Line Items]
Interest rate	3.80%
June 2018 Debt issuance 3.80% coupon Due 2028 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances	$ 600,000,000
January 2017 Issuance Maturing January 2020 [Member]
Debt Instrument [Line Items]
Interest rate		1.85%
January 2017 Issuance Maturing January 2020 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances		$ 250,000,000
March 2017 Issuance Maturing June 2046 [Member]
Debt Instrument [Line Items]
Interest rate		3.70%
March 2017 Issuance Maturing June 2046 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances		$ 100,000,000
September 2017 Issuance Maturing September 2020 [Member]
Debt Instrument [Line Items]
Interest rate		1.50%
September 2017 Issuance Maturing September 2020 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances		$ 300,000,000
November 2017 Issuance Maturing December 2047 [Member]
Debt Instrument [Line Items]
Interest rate		3.70%
November 2017 Issuance Maturing December 2047 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances		$ 550,000,000
November 2018 Debt Issuance 3.950% Coupon Due 2028 [Member]
Debt Instrument [Line Items]
Interest rate	3.95%
November 2018 Debt Issuance 3.950% Coupon Due 2028 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances	$ 650,000,000
September 2017 Issuance Maturing September 2047 [Member]
Debt Instrument [Line Items]
Interest rate		3.60%
September 2017 Issuance Maturing September 2047 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances		$ 500,000,000
Parent Company [Member]
Debt Instrument [Line Items]
Debt issuances	1,250,000,000	2,500,000,000
Parent Company [Member] | April 2017 Issuance Maturing April 2025 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuances		420,000,000
Repayments of Debt		400,000,000
Parent Company [Member] | June 2017 Issuance Maturing June 2020 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuances		330,000,000
Repayments of Debt		700,000,000
Parent Company [Member] | August 2017 Issuance Maturing August 2022 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuances		500,000,000
Parent Company [Member] | August 2017 Issuance Maturing August 2027 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuances		750,000,000
Parent Company [Member] | August 2017 Issuance Maturing August 2047 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuances		500,000,000
Parent Company [Member] | March 2018 Debt Issuance 3.950% Coupon Due 2025 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuances	250,000,000
Parent Company [Member] | May 2018 Debt Issuance 2.819% Coupon Due 2021 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuances	500,000,000
Parent Company [Member] | September 2018 Debt Issuance 5.625% Coupon Due 2078 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuances	500,000,000
Duke Energy Carolinas [Member]
Debt Instrument [Line Items]
Debt issuances	2,000,000,000	550,000,000
Duke Energy Carolinas [Member] | First Mortgage Bonds Maturing April 2018, 5.100% Coupon [Member]
Debt Instrument [Line Items]
Repayments of Debt	300,000,000
Duke Energy Carolinas [Member] | November 2018 Debt Issuance 3.350% Coupon Due 2022 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances	350,000,000
Duke Energy Carolinas [Member] | March 2018 Debt Issuance 3.050% Coupon Due 2023 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances	500,000,000
Duke Energy Carolinas [Member] | March 2018 Debt Issuance 3.950% Coupon Due 2048 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances	500,000,000
Duke Energy Carolinas [Member] | November 2017 Issuance Maturing December 2047 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances		550,000,000
Repayments of Debt		400,000,000
Duke Energy Carolinas [Member] | November 2018 Debt Issuance 3.950% Coupon Due 2028 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances	650,000,000
Duke Energy Progress [Member]
Debt Instrument [Line Items]
Debt issuances	800,000,000	800,000,000
Duke Energy Progress [Member] | August 2018 Debt Issuance 3.375% Coupon Due 2023 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances	300,000,000
Duke Energy Progress [Member] | August 2018 Debt Issuance 3.700% Coupon Due 2028 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances	500,000,000
Duke Energy Progress [Member] | September 2017 Issuance Maturing September 2020 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances		300,000,000
Repayments of Debt		200,000,000
Duke Energy Progress [Member] | September 2017 Issuance Maturing September 2047 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances		500,000,000
Duke Energy Florida [Member]
Debt Instrument [Line Items]
Debt issuances	1,000,000,000	1,300,000,000
Duke Energy Florida [Member] | January 2017 Issuance Maturing January 2027 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances		650,000,000
Duke Energy Florida [Member] | December 2017 Issuance Maturing December 2019 [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt issuances		400,000,000
Duke Energy Florida [Member] | June 2018 Debt Issuance 4.20 Coupon Due 2048 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances	400,000,000
Duke Energy Florida [Member] | June 2018 Debt issuance 3.80% coupon Due 2028 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances	$ 600,000,000
Duke Energy Florida [Member] | January 2017 Issuance Maturing January 2020 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances		250,000,000
Repayments of Debt		250,000,000
Duke Energy Ohio [Member]
Debt Instrument [Line Items]
Debt issuances		100,000,000
Duke Energy Ohio [Member] | March 2017 Issuance Maturing June 2046 [Member] | First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Debt issuances		$ 100,000,000