Debt and Credit Facilities Debt and Credit Facilities (Summary of Current Maturities of Long-term Debt)(Details) (USD $) In Millions, unless otherwise specified			6 Months Ended				6 Months Ended					6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2014 Unsecured Debt [Member] July 2014 Maturity 1 [Member]	Jun. 30, 2014 Other Debt Obligations [Member]	Jun. 30, 2014 Duke Energy Progress [Member]	Dec. 31, 2013 Duke Energy Progress [Member]	Jun. 30, 2014 Duke Energy Progress [Member] First Mortgage Bonds [Member] April 2015 Maturity 1 [Member]	Jun. 30, 2014 Parent Company [Member] Unsecured Debt [Member] September 2014 Maturity [Member]	Jun. 30, 2014 Parent Company [Member] Unsecured Debt [Member] April 2015 Maturity 1 [Member]	Jun. 30, 2014 Duke Energy Ohio [Member]	Dec. 31, 2013 Duke Energy Ohio [Member]	Jun. 30, 2014 Duke Energy Ohio [Member] First Mortgage Bonds [Member] March 2015 [Member]
Debt Instrument [Line Items]
Debt maturity date			Jul. 31, 2014				Apr. 30, 2015	Sep. 30, 2014	Apr. 30, 2015			Mar. 31, 2015
Interest rate			15.37%				5.15%	3.95%	3.35%			0.37%
Current maturities of long-term debt	$ 1,887	$ 2,104	$ 196	$ 291	$ 306	$ 174	$ 300	$ 500	$ 450	$ 197	$ 47	$ 150