Asset Retirement Obligations (NDTF Requirements)(Details) (USD $) In Millions, unless otherwise specified					12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Duke Energy Carolinas [Member]	Dec. 31, 2012 Duke Energy Carolinas [Member]	Dec. 31, 2013 Duke Energy Carolinas [Member] 2013 Cost Study [Member]		Dec. 31, 2013 Duke Energy Progress [Member] 2009 Cost Study [Member]		Dec. 31, 2013 Duke Energy Florida [Member] 2013 Cost Study [Member]
NDTF, Funding Requirements [Abstract]
Decommissioning contribution requirement					$ 21		$ 14
Decommissioning cost study estimate					3,420	[1],[2]	3,000	[1],[2]	1,083	[1],[2]
NDTF, Legally Restricted Assets, Fair Value [Abstract]
Legally restricted NDTF investments, fair value	$ 4,769	$ 3,941	$ 2,477	$ 2,053

[1] Represents cost per the most recent site-specific nuclear decommissioning cost studies, including costs to decommission plant components not subject to radioactive contamination.

[2] Includes the Duke Energy Registrants' ownership interest in jointly owned reactors. Other joint owners are responsible for decommissioning costs related to their interest in the reactors.