Regulatory Matters (Schedule of Net Carrying Value Of Facilities As Well As the Remaining Non-current Regulatory Assets) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013 MW
Megawatt of potential plants to be retired	3,244
Remaining net book value of potential plants to be retired	$ 326	[1]
Duke Energy Carolinas [Member]
Megawatt of potential plants to be retired	200	[2]
Remaining net book value of potential plants to be retired	15	[1],[2],[3]
Retired MW
Megawatts committed to be retired
Progress Energy [Member]
Megawatt of potential plants to be retired	1,448
Remaining net book value of potential plants to be retired	173	[1]
Duke Energy Progress [Member]
Megawatt of potential plants to be retired	575	[4]
Remaining net book value of potential plants to be retired	61	[1],[3],[4]
Duke Energy Florida [Member]
Megawatt of potential plants to be retired	873	[5]
Remaining net book value of potential plants to be retired	112	[1],[5]
Duke Energy Ohio [Member]
Megawatt of potential plants to be retired	928	[6]
Remaining net book value of potential plants to be retired	11	[1],[6]
Duke Energy Indiana [Member]
Megawatt of potential plants to be retired	668	[7]
Remaining net book value of potential plants to be retired	$ 127	[1],[7]

[1] Included in Property, plant and equipment, net as of June 30, 2013, on the Condensed Consolidated Balance Sheets, unless otherwise noted.

[2] Includes Lee Units 1 and 2. Excludes 170 MW Lee Unit 3 that is expected to be converted to gas in 2014.

[3] Remaining net book value of Duke Energy Progress' Sutton Station is included in Generation facilities to be retired, net, on the Condensed Consolidated Balance Sheets at June 30, 2013.

[4] Includes Sutton Station, which is expected to be retired by the end of 2013.

[5] Includes Crystal River Units 1 and 2.

[6] Includes Beckjord Station Units 2 through 6 and Miami Fort Unit 6. Beckjord has no remaining book value.

[7] Includes Wabash River Units 2 through 6. Wabash River Unit 6 is being evaluated for potential conversion to gas.