Stockholders' Equity (Earnings Per Share Data) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Equity [Abstract]
Income from continuing operations available to Duke Energy common stockholders excluding impact of participating securities and including accumulated preferred stock dividends									$ 3,694	$ 2,642	$ 3,059
Weighted average common shares outstanding – basic and diluted									729	708	700
EPS from continuing operations available to Duke Energy common stockholders, Basic and diluted (in usd per share)	$ 0.89	$ 1.82	$ 1.12	$ 1.24	$ 0.62	$ 1.51	$ 0.72	$ 0.88	$ 5.07	$ 3.73	$ 4.37
Potentially dilutive items excluded from the calculation(in shares)									2	2	2
Dividends declared per share (usd per share)									$ 3.75	$ 3.64	$ 3.49
Dividends declared on Series A preferred stock per depositary share (in usd per share)									$ 1.03