Stockholders' Equity (Earnings Per Share Data) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Class of Stock [Line Items]
Income from continuing operations available to Duke Energy common stockholders excluding impact of participating securities and including accumulated preferred stock dividends adjustment	$ 911	$ 898
Weighted average common shares outstanding – basic (in shares)	734	727
Equity Forwards (in shares)	2
Weighted average common shares outstanding – diluted (in shares)	736	727
Basic and diluted (in usd per share)	$ 1.24	$ 1.24
Potentially dilutive items excluded from the calculation (in shares)	2	2
Common Stock
Class of Stock [Line Items]
Dividends declared per common share (in usd per share)	$ 0.945	$ 0.9275
Preferred stock, Series A
Class of Stock [Line Items]
Dividends declared on preferred stock per depositary share (in usd per share)	$ 0.359
Cumulative dividend rate per annum	5.75%
Price per share (in usd per share)	$ 25
Preferred stock, Series B
Class of Stock [Line Items]
Dividends declared on preferred stock per depositary share (in usd per share)	$ 24.917
Cumulative dividend rate per annum	4.875%
Liquidation preference per share (in usd per share)	$ 1,000