Earnings Per Share (Tables)

3 Months Ended

Mar. 31, 2013

Earnings Per Share [Line Items]

Schedule Of Earnings Per Share

(In millions, except per-share amounts)	Income		Average Shares		EPS
Three Months Ended March 31, 2013
Income from continuing operations attributable to Duke Energy common shareholders, as adjusted for participating securities — basic and diluted	$	629		705	$	0.89
Three Months Ended March 31, 2012
Income from continuing operations attributable to Duke Energy common shareholders, as adjusted for participating securities — basic and diluted	$	292		446	$	0.65