Stockholders' Equity (Earnings Per Share Data) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Class of Stock [Line Items]
Net income available to Duke Energy common stockholders	$ 953	$ 899
Accumulated preferred stock dividends adjustment	12	13
Less: Impact of participating securities	1	1
Income from continuing operations available to Duke Energy common stockholders	$ 964	$ 911
Weighted average common shares outstanding – basic (in shares)	769	734
Equity forwards (in shares)	0	2
Weighted average common shares outstanding – diluted (in shares)	769	736
EPS available to Duke Energy common stockholders
Basic (in usd per share)	$ 1.25	$ 1.24
Diluted (in usd per share)	$ 1.25	$ 1.24
Potentially dilutive items excluded from the calculation (in shares)	2	2
Common Stock
EPS available to Duke Energy common stockholders
Dividends declared per common share (in usd per share)	$ 0.965	$ 0.945
Preferred stock, Series A
EPS available to Duke Energy common stockholders
Dividends declared on preferred stock per depositary share (in usd per share)	$ 0.359	0.359
Cumulative dividend rate per annum	5.75%
Liquidation preference per share (in usd per share)	$ 25
Preferred stock, Series B
EPS available to Duke Energy common stockholders
Dividends declared on preferred stock per depositary share (in usd per share)	$ 24.375	$ 24.917
Cumulative dividend rate per annum	4.875%
Liquidation preference per share (in usd per share)	$ 1,000