Stockholders' Equity (Earnings Per Share Data) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Class of Stock [Line Items]
Net income (loss) available to Duke Energy common stockholders	$ 751	$ (817)	$ 1,704	$ 82
Accumulated preferred stock dividends adjustment	(12)	(12)
Less: Impact of participating securities	1		1
Income (loss) from continuing operations available to Duke Energy common stockholders	$ 738	$ (829)	$ 1,703	$ 82
Weighted average common shares outstanding – basic (in shares)	769	735	769	734
Equity forwards (in shares)				1
Weighted average common shares outstanding – diluted (in shares)	769	735	769	735
Earnings (Loss) Per Share available to Duke Energy common stockholders
Basic (in usd per share)	$ 0.96	$ (1.13)	$ 2.21	$ 0.11
Diluted (in usd per share)	$ 0.96	$ (1.13)	$ 2.21	$ 0.11
Potentially dilutive items excluded from the calculation (in shares)	2	2	2	2
Common Stock
Earnings (Loss) Per Share available to Duke Energy common stockholders
Dividends declared per common share (in usd per share)	$ 0.965	$ 0.945	$ 1.930	$ 1.890
Preferred stock, Series A
Earnings (Loss) Per Share available to Duke Energy common stockholders
Dividends declared on preferred stock per depositary share (in usd per share)	0.359	$ 0.359	$ 0.719	0.719
Cumulative dividend rate per annum			5.75%
Liquidation preference per share (in usd per share)	25		$ 25
Preferred stock, Series B
Earnings (Loss) Per Share 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		$ 1,000