Debt and Credit Facilities (Summary of Debt Issuances) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Debt Instrument [Line Items]
Debt issuances	$ 5,310,000,000
Repayments of long-term debt	2,737,000,000	$ 2,278,000,000
Parent Company [Member]
Debt Instrument [Line Items]
Debt issuances	1,800,000,000
Duke Energy Carolinas [Member]
Debt Instrument [Line Items]
Debt issuances	800,000,000
Repayments of long-term debt	5,000,000	704,000,000
Duke Energy Progress [Member]
Debt Instrument [Line Items]
Debt issuances	600,000,000
Repayments of long-term debt	603,000,000	2,000,000
Duke Energy Florida [Member]
Debt Instrument [Line Items]
Repayments of long-term debt	210,000,000	717,000,000
Duke Energy Ohio [Member]
Debt Instrument [Line Items]
Debt issuances	1,010,000,000
Repayments of long-term debt	451,000,000	3,000,000
Duke Energy Ohio [Member] | April 2019 First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Repayments of long-term debt	450,000,000
Duke Energy Ohio [Member] | Debentures Due October 2019 [Member]
Debt Instrument [Line Items]
Repayments of long-term debt	100,000,000
Duke Energy Indiana [Member]
Debt Instrument [Line Items]
Debt issuances	500,000,000
Repayments of long-term debt	60,000,000	$ 1,000,000
Duke Energy Indiana [Member] | Pollution Control Bonds [Member]
Debt Instrument [Line Items]
Repayments of long-term debt	150,000,000
Piedmont Natural Gas [Member]
Debt Instrument [Line Items]
Debt issuances	600,000,000
Repayments of long-term debt	350,000,000
Piedmont Natural Gas [Member] | Senior Unsecured Term Loan Facility Due September 2019 [Member]
Debt Instrument [Line Items]
Repayments of long-term debt	350,000,000
Unsecured Debt [Member] | March 2019 Debt Issuance 3.250% Coupon Due 2022 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 300,000,000
Interest rate	2.788%
Unsecured Debt [Member] | March 2019 Debt Issuance 3.227% Coupon Due 2022 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 300,000,000
Interest rate	3.227%
Unsecured Debt [Member] | May 2019 Debt Issuance 3.500% Coupon Due 2029 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 600,000,000
Interest rate	3.50%
Unsecured Debt [Member] | June 2019 Debt Issuance 3.400% Coupon Due 2029 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 600,000,000
Interest rate	3.40%
Unsecured Debt [Member] | June 2019 Debt Issuance 4.200% Coupon Due 2049 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 600,000,000
Interest rate	4.20%
Unsecured Debt [Member] | July 2019 Debt Issuance 4.320% Coupon Due 2049 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 40,000,000
Interest rate	4.32%
Unsecured Debt [Member] | September 2019 Debt Issuance 3.230% Coupon Due 2025 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 95,000,000
Interest rate	3.23%
Unsecured Debt [Member] | September 2019 Debt Issuance 3.560% Coupon Due 2029 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 75,000,000
Interest rate	3.56%
Unsecured Debt [Member] | Parent Company [Member] | March 2019 Debt Issuance 3.250% Coupon Due 2022 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 300,000,000
Unsecured Debt [Member] | Parent Company [Member] | March 2019 Debt Issuance 3.227% Coupon Due 2022 [Member]
Debt Instrument [Line Items]
Debt issuances	300,000,000
Unsecured Debt [Member] | Parent Company [Member] | June 2019 Debt Issuance 3.400% Coupon Due 2029 [Member]
Debt Instrument [Line Items]
Debt issuances	600,000,000
Unsecured Debt [Member] | Parent Company [Member] | June 2019 Debt Issuance 4.200% Coupon Due 2049 [Member]
Debt Instrument [Line Items]
Debt issuances	600,000,000
Unsecured Debt [Member] | Duke Energy Ohio [Member] | July 2019 Debt Issuance 4.320% Coupon Due 2049 [Member]
Debt Instrument [Line Items]
Debt issuances	40,000,000
Unsecured Debt [Member] | Duke Energy Ohio [Member] | September 2019 Debt Issuance 3.230% Coupon Due 2025 [Member]
Debt Instrument [Line Items]
Debt issuances	95,000,000
Unsecured Debt [Member] | Duke Energy Ohio [Member] | September 2019 Debt Issuance 3.560% Coupon Due 2029 [Member]
Debt Instrument [Line Items]
Debt issuances	75,000,000
Unsecured Debt [Member] | Piedmont Natural Gas [Member] | May 2019 Debt Issuance 3.500% Coupon Due 2029 [Member]
Debt Instrument [Line Items]
Debt issuances	600,000,000
First Mortgage [Member] | January 2019 Debt Issuance 3.650% Coupon Due 2029 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 400,000,000
Interest rate	3.65%
First Mortgage [Member] | January 2019 Debt Issuance 4.300% Coupon Due 2049 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 400,000,000
Interest rate	4.30%
First Mortgage [Member] | March 2019 Debt Issuance 3.450% Coupon Due 2029 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 600,000,000
Interest rate	3.45%
First Mortgage [Member] | August 2019 Debt Issuance 2.450% Coupon Due 2029 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 450,000,000
Interest rate	2.45%
First Mortgage [Member] | August 2019 Debt Issuance 3.200% Coupon Due 2049 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 350,000,000
Interest rate	3.20%
First Mortgage [Member] | September 2019 Debt Issuance 3.250% Coupon Due 2049 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 500,000,000
Interest rate	3.25%
First Mortgage [Member] | Duke Energy Carolinas [Member] | August 2019 Debt Issuance 2.450% Coupon Due 2029 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 450,000,000
First Mortgage [Member] | Duke Energy Carolinas [Member] | August 2019 Debt Issuance 3.200% Coupon Due 2049 [Member]
Debt Instrument [Line Items]
Debt issuances	350,000,000
First Mortgage [Member] | Duke Energy Progress [Member] | March 2019 Debt Issuance 3.450% Coupon Due 2029 [Member]
Debt Instrument [Line Items]
Debt issuances	600,000,000
First Mortgage [Member] | Duke Energy Ohio [Member] | January 2019 Debt Issuance 3.650% Coupon Due 2029 [Member]
Debt Instrument [Line Items]
Debt issuances	400,000,000
First Mortgage [Member] | Duke Energy Ohio [Member] | January 2019 Debt Issuance 4.300% Coupon Due 2049 [Member]
Debt Instrument [Line Items]
Debt issuances	400,000,000
First Mortgage [Member] | Duke Energy Indiana [Member] | September 2019 Debt Issuance 3.250% Coupon Due 2049 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 500,000,000