Stockholders' Equity (Earnings Per Share Data) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Class of Stock [Line Items]
Net income available to Duke Energy common stockholders	$ 1,366	$ 1,265	$ 3,070	$ 1,347
Accumulated preferred stock dividends adjustment	12	12	12	13
Less: Impact of participating securities	1	1	3	2
Income from continuing operations available to Duke Energy common stockholders	$ 1,377	$ 1,276	$ 3,079	$ 1,358
Weighted average common shares outstanding – basic (in shares)	769	735	769	735
Diluted (in shares)	769	735	769	735
EPS available to Duke Energy common stockholders
Basic (in usd per share)	$ 1.79	$ 1.74	$ 4.00	$ 1.85
Diluted (in usd per share)	$ 1.79	$ 1.74	$ 4.00	$ 1.85
Potentially dilutive items excluded from the calculation (in shares)	2	2	2	2
Common Stock
EPS available to Duke Energy common stockholders
Dividends declared per common share (in usd per share)	$ 0.985	$ 0.965	$ 2.915	$ 2.855
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	$ 1.078	1.078
Cumulative dividend rate per annum			5.75%
Liquidation preference per share (in usd per share)	25		$ 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	$ 24.375	$ 48.750	$ 49.292
Cumulative dividend rate per annum			4.875%
Liquidation preference per share (in usd per share)	$ 1,000		$ 1,000