Stockholders' Equity (Earnings Per Share Data) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Class of Stock [Line Items]
Income from continuing operations attributable to Duke Energy common stockholders excluding impact of participating securities	$ 1,324	$ 1,077	$ 3,041	$ 2,199
Weighted average common shares outstanding – basic (in shares)	729	713	728	705
Equity Forwards (in shares)		1		1
Weighted average common shares outstanding – diluted (in shares)	729	714	728	706
Basic (in usd per share)	$ 1.82	$ 1.51	$ 4.18	$ 3.12
Diluted (in usd per share)	$ 1.82	$ 1.51	$ 4.18	$ 3.11
Potentially dilutive items excluded from the calculation (in shares)	2	2	2	2
Common Stock [Member]
Class of Stock [Line Items]
Dividends declared per common share (in usd per share)	$ 0.945	$ 0.9275	$ 2.800	$ 2.7075
Depositary Share [Member]
Class of Stock [Line Items]
Dividends declared on preferred stock per depositary share (in usd per share)	$ 0.359		$ 0.667