Committments and Contingencies (Schedule of Reserves and Insurance Recoveries) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Loss Contingencies [Line Items]
Reserves for legal matters	$ 817	[1],[2]	$ 824	[1],[2]
Probable insurance recoveries	649	[3],[4]	649	[3],[4]
Duke Energy Carolinas [Member]
Loss Contingencies [Line Items]
Reserves for legal matters	609	[1],[2]	616	[1],[2]
Probable insurance recoveries	649	[3],[4]	649	[3],[4]
Progress Energy [Member]
Loss Contingencies [Line Items]
Reserves for legal matters	78	[1]	78	[1]
Duke Energy Progress [Member]
Loss Contingencies [Line Items]
Reserves for legal matters	10	[1]	10	[1]
Duke Energy Florida [Member]
Loss Contingencies [Line Items]
Reserves for legal matters	43	[1]	43	[1]
Duke Energy Indiana [Member]
Loss Contingencies [Line Items]
Reserves for legal matters	$ 8	[1]	$ 8	[1]

[1] Reserves are classified on the Condensed Consolidated Balance Sheets in Other within Deferred Credits and Other Liabilities and Other within Current Liabilities.

[2] Includes reserves for asbestos-related injuries and damages claims.

[3] Insurance recoveries are classified on the Condensed Consolidated Balance Sheets in Receivables and Other within Investments and Other Assets.

[4] Relates to recoveries associated with asbestos-related injuries and damages claims.