Common Stock (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Earnings Per Share [Line Items]
Average shares, basic									706	574	444
Average shares, diluted									706	575	444
EPS, basic	$ 0.96	$ 1.40	$ 0.48	$ 0.89	$ 0.57	$ 0.84	$ 0.99	$ 0.66	$ 3.74	$ 3.01	$ 3.83
EPS, diluted	$ 0.96	$ 1.40	$ 0.48	$ 0.89	$ 0.57	$ 0.84	$ 0.99	$ 0.66	$ 3.74	$ 3.01	$ 3.83
Number of stock options and performance and unvested stock awards excluded from the dilutive securities calculation									2	1	3
Dividends declared per share									$ 3.09	$ 3.03	$ 2.97
Income [Member]
Earnings Per Share [Line Items]
Income from continuing operations attributable to Duke Energy common stockholders, as adjusted for participating securities - basic and diluted									$ 2,640	$ 1,727	$ 1,702
Average Shares [Member]
Earnings Per Share [Line Items]
Stock options, performance and restricted stock										1
Average shares, basic and diluted									706		444
Average shares, basic										574
Average shares, diluted										575
EPS [Member]
Earnings Per Share [Line Items]
EPS, basic and diluted									$ 3.74		$ 3.83
EPS, basic										$ 3.01
EPS, diluted										$ 3.01