Stockholders' Equity (Earnings Per Share Data) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Class of Stock [Line Items]
Net income available to Duke Energy common stockholders	$ 1,265	$ 1,327	$ 1,347	$ 3,047
Accumulated preferred stock dividends adjustment	12	(2)	13	(2)
Less: Impact of participating securities	1	1	2	4
Income from continuing operations available to Duke Energy common stockholders	$ 1,276	$ 1,324	$ 1,358	$ 3,041
Weighted average common shares outstanding – basic (in shares)	735	729	735	728
Weighted average common shares outstanding – diluted (in shares)	735	729	735	728
EPS available to Duke Energy common stockholders
Basic and diluted (in usd per share)	$ 1.74	$ 1.82	$ 1.85	$ 4.18
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)	$ 0.965	$ 0.945	$ 2.855	$ 2.800
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	$ 0.667
Cumulative dividend rate per annum			5.75%
Price 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		$ 49.292
Cumulative dividend rate per annum			4.875%
Liquidation preference per share (in usd per share)	$ 1,000		$ 1,000