Regulatory Matters (Duke Energy Florida Narrative) (Details)			1 Months Ended	3 Months Ended	12 Months Ended
	Jan. 14, 2021 USD ($)	Jul. 01, 2020 USD ($) plant MW	Oct. 31, 2015 USD ($) MW	Dec. 31, 2018 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	May 19, 2020 USD ($)	Apr. 02, 2020 USD ($)	Dec. 19, 2019 USD ($)	Nov. 22, 2019 USD ($)	Apr. 30, 2019 USD ($)
Public Utilities, General Disclosures [Line Items]
Regulatory assets								$ 14,062,000,000	$ 15,018,000,000
Impairment charges								984,000,000	(8,000,000)	$ 402,000,000
Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Regulatory assets								2,064,000,000	2,613,000,000
Impairment charges								(4,000,000)	(36,000,000)	$ 54,000,000
Hurricane Dorian Storm Damage | Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Estimated storm costs, capital and operation maintenance									167,000,000				$ 169,000,000
FPSC | Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Accelerated fuel cost refund												$ 78,000,000
Solar generation capacity plants (in MW) | MW		750
Number of solar plants petition for approval | plant		10
FPSC | 2021 Settlement | Duke Energy Florida | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Approved rate increase (decrease) amount by state commission					$ 79,000,000	$ 49,000,000	$ 67,000,000
Approved capital structure, percentage	53.00%
Approved debt structure, percentage	47.00%
Public utilities, basis points, increase	0.25%
Contract asset, noncurrent	$ 173,000,000
Future investments in new cost	$ 1,000,000,000
FPSC | 2021 Settlement | Duke Energy Florida | US Treasury Securities | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Public utilities, basis points, increase	0.50%
FPSC | 2021 Settlement | Duke Energy Florida | Minimum | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Approved return on equity, percentage	8.85%
FPSC | 2021 Settlement | Duke Energy Florida | Minimum | US Treasury Securities | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Approved return on equity, percentage	9.85%
FPSC | 2021 Settlement | Duke Energy Florida | Maximum | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Approved return on equity, percentage	10.85%
FPSC | 2021 Settlement | Duke Energy Florida | Maximum | US Treasury Securities | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Approved return on equity, percentage	10.10%
FPSC | 2021 Settlement | Duke Energy Florida | Weighted Average | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Approved return on equity, percentage	9.85%
FPSC | Hurricane Michael Storm Damage | Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Estimated storm costs, capital and operation maintenance															$ 223,000,000
Amount of recovery costs sought											$ 188,000,000			$ 191,000,000
Storm deferral - requested supplemental true-up											$ 3,000,000
FPSC | Hurricane Dorian Storm Damage | Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Storm Costs - Capital and Operation Maintenance								145,000,000
Solar Plant | Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Estimated cost of generation facilities to be built		$ 1,000,000,000
Estimated cost of generation facilities to be built, period		4 years
Natural Gas Plant | Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Estimated cost of generation facilities to be built			$ 1,500,000,000
Natural gas generation capacity plants (in MW) | MW			1,640
Cost of generation facilities to be built			$ 1,600,000,000
Impairment charges				$ 60,000,000
Impairment cost reversal									36,000,000
Storm cost deferrals
Public Utilities, General Disclosures [Line Items]
Regulatory assets								1,102,000,000	1,399,000,000
Storm cost deferrals | Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Regulatory assets								108,000,000	413,000,000
Storm cost deferrals | Hurricane Michael Storm Damage | Duke Energy Florida
Public Utilities, General Disclosures [Line Items]
Regulatory assets								$ 80,000,000	$ 204,000,000