Earnings Per Share (Tables)

9 Months Ended

Sep. 30, 2012

Earnings Per Share [Abstract]

Schedule Of Earnings Per Share

			Average
(in millions, except per-share amounts)	Income		Shares			EPS
Three Months Ended September 30, 2012
Income from continuing operations attributable to Duke Energy common shareholders, as adjusted for participating securities — basic and diluted	$	589		699	$	0.84
Three Months Ended September 30, 2011
Income from continuing operations attributable to Duke Energy common shareholders, as adjusted for participating securities — basic and diluted	$	471		444	$	1.06

			Average
(In millions, except per-share amounts)	Income		Shares		EPS
Nine Months Ended September 30, 2012
Income from continuing operations attributable to Duke Energy common shareholders, as adjusted for participating securities — basic and diluted	$	1,326		531	$	2.50
Nine Months Ended September 30, 2011
Income from continuing operations attributable to Duke Energy common shareholders, as adjusted for participating securities — basic and diluted	$	1,415		444	$	3.19