Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Receivables, allowance for doubtful accounts	$ 31	$ 34
Restricted receivables, allowance for doubtful accounts	42	44
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	2,000,000,000	2,000,000,000
Common stock, shares outstanding	706,000,000	704,000,000
Duke Energy Carolinas [Member]
Receivables, allowance for doubtful accounts	3	3
Restricted receivables, allowance for doubtful accounts	6	6
Progress Energy [Member]
Receivables, allowance for doubtful accounts	14	16
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	100	100
Common stock, shares outstanding	100	100
Duke Energy Progress [Member]
Receivables, allowance for doubtful accounts	9	9
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares outstanding	160,000,000	160,000,000
Duke Energy Florida [Member]
Receivables, allowance for doubtful accounts	4	7
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares outstanding	100	100
Duke Energy Ohio [Member]
Receivables, allowance for doubtful accounts	2	2
Common stock, par value	$ 8.50	$ 8.50
Common stock, shares authorized	120,000,000	120,000,000
Common stock, shares outstanding	89,663,086	89,663,086
Duke Energy Indiana [Member]
Receivables, allowance for doubtful accounts	$ 1	$ 1
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares outstanding	53,913,701	53,913,701