Fair Value Measurements (Quantitative Level 3 Fair Value Disclosure) (Details) (USD $) In Millions, unless otherwise specified									6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended		12 Months Ended				6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended			6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended			6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended										6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended																						6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended			6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended											6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Apr. 01, 2014	Dec. 31, 2013	Jun. 30, 2013	Apr. 01, 2013	Dec. 31, 2012	Jun. 30, 2014 Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member]	Dec. 31, 2013 Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member]	Jun. 30, 2014 Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2013 Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member] Minimum [Member]	Jun. 30, 2014 Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member] Maximum [Member]	Dec. 31, 2013 Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member] Maximum [Member]	Dec. 31, 2013 FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member]	Dec. 31, 2013 FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2013 FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member] Maximum [Member]	Jun. 30, 2014 Financial Transmission Rights [Member] RTO Market Pricing [Member]	Dec. 31, 2013 Financial Transmission Rights [Member] RTO Market Pricing [Member]	Jun. 30, 2014 Financial Transmission Rights [Member] RTO Market Pricing [Member] Minimum [Member]	Dec. 31, 2013 Financial Transmission Rights [Member] RTO Market Pricing [Member] Minimum [Member]	Jun. 30, 2014 Financial Transmission Rights [Member] RTO Market Pricing [Member] Maximum [Member]	Dec. 31, 2013 Financial Transmission Rights [Member] RTO Market Pricing [Member] Maximum [Member]	Jun. 30, 2014 Commodity Power Contracts [Member] Discounted Cash Flow [Member]	Dec. 31, 2013 Commodity Power Contracts [Member] Discounted Cash Flow [Member]	Jun. 30, 2014 Commodity Power Contracts [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2013 Commodity Power Contracts [Member] Discounted Cash Flow [Member] Minimum [Member]	Jun. 30, 2014 Commodity Power Contracts [Member] Discounted Cash Flow [Member] Maximum [Member]	Dec. 31, 2013 Commodity Power Contracts [Member] Discounted Cash Flow [Member] Maximum [Member]	Jun. 30, 2014 Commodity Capacity Option Contracts [Member] Discounted Cash Flow [Member]	Dec. 31, 2013 Commodity Capacity Option Contracts [Member] Discounted Cash Flow [Member]	Jun. 30, 2014 Commodity Capacity Option Contracts [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2013 Commodity Capacity Option Contracts [Member] Discounted Cash Flow [Member] Minimum [Member]	Jun. 30, 2014 Commodity Capacity Option Contracts [Member] Discounted Cash Flow [Member] Maximum [Member]	Dec. 31, 2013 Commodity Capacity Option Contracts [Member] Discounted Cash Flow [Member] Maximum [Member]	Jun. 30, 2014 Derivative Financial Instruments Liabilities Reserves [Member]	Dec. 31, 2013 Derivative Financial Instruments Liabilities Reserves [Member]	Jun. 30, 2014 Duke Energy Carolinas [Member]	Apr. 01, 2014 Duke Energy Carolinas [Member]	Dec. 31, 2013 Duke Energy Carolinas [Member]	Jun. 30, 2013 Duke Energy Carolinas [Member]	Apr. 01, 2013 Duke Energy Carolinas [Member]	Dec. 31, 2012 Duke Energy Carolinas [Member]	Dec. 31, 2013 Duke Energy Carolinas [Member] FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member]	Jun. 30, 2014 Duke Energy Carolinas [Member] FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2013 Duke Energy Carolinas [Member] FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member] Minimum [Member]	Jun. 30, 2014 Duke Energy Carolinas [Member] FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member] Maximum [Member]	Dec. 31, 2013 Duke Energy Carolinas [Member] FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member] Maximum [Member]	Jun. 30, 2014 Duke Energy Carolinas [Member] Commodity Power Contracts [Member] Discounted Cash Flow [Member]	Jun. 30, 2014 Progress Energy [Member]	Apr. 01, 2014 Progress Energy [Member]	Dec. 31, 2013 Progress Energy [Member]	Jun. 30, 2013 Progress Energy [Member]	Apr. 01, 2013 Progress Energy [Member]	Dec. 31, 2012 Progress Energy [Member]	Jun. 30, 2014 Duke Energy Progress [Member]	Apr. 01, 2014 Duke Energy Progress [Member]	Dec. 31, 2013 Duke Energy Progress [Member]	Jun. 30, 2013 Duke Energy Progress [Member]	Apr. 01, 2013 Duke Energy Progress [Member]	Dec. 31, 2012 Duke Energy Progress [Member]	Jun. 30, 2014 Duke Energy Ohio [Member]	Apr. 01, 2014 Duke Energy Ohio [Member]	Dec. 31, 2013 Duke Energy Ohio [Member]	Jun. 30, 2013 Duke Energy Ohio [Member]	Apr. 01, 2013 Duke Energy Ohio [Member]	Dec. 31, 2012 Duke Energy Ohio [Member]	Jun. 30, 2014 Duke Energy Ohio [Member] Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member]	Dec. 31, 2013 Duke Energy Ohio [Member] Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member]	Jun. 30, 2014 Duke Energy Ohio [Member] Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2013 Duke Energy Ohio [Member] Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member] Minimum [Member]	Jun. 30, 2014 Duke Energy Ohio [Member] Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member] Maximum [Member]	Dec. 31, 2013 Duke Energy Ohio [Member] Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member] Maximum [Member]	Jun. 30, 2014 Duke Energy Ohio [Member] Commodity Power Contracts [Member] Discounted Cash Flow [Member]	Dec. 31, 2013 Duke Energy Ohio [Member] Commodity Power Contracts [Member] Discounted Cash Flow [Member]	Jun. 30, 2014 Duke Energy Ohio [Member] Commodity Power Contracts [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2013 Duke Energy Ohio [Member] Commodity Power Contracts [Member] Discounted Cash Flow [Member] Minimum [Member]	Jun. 30, 2014 Duke Energy Ohio [Member] Commodity Power Contracts [Member] Discounted Cash Flow [Member] Maximum [Member]	Dec. 31, 2013 Duke Energy Ohio [Member] Commodity Power Contracts [Member] Discounted Cash Flow [Member] Maximum [Member]	Jun. 30, 2014 Duke Energy Ohio [Member] Derivative Financial Instruments Liabilities Reserves [Member]	Dec. 31, 2013 Duke Energy Ohio [Member] Derivative Financial Instruments Liabilities Reserves [Member]	Jun. 30, 2014 Duke Energy Indiana [Member]	Apr. 01, 2014 Duke Energy Indiana [Member]	Dec. 31, 2013 Duke Energy Indiana [Member]	Jun. 30, 2013 Duke Energy Indiana [Member]	Apr. 01, 2013 Duke Energy Indiana [Member]	Dec. 31, 2012 Duke Energy Indiana [Member]	Jun. 30, 2014 Duke Energy Indiana [Member] Financial Transmission Rights [Member] RTO Market Pricing [Member]	Dec. 31, 2013 Duke Energy Indiana [Member] Financial Transmission Rights [Member] RTO Market Pricing [Member]	Jun. 30, 2014 Duke Energy Indiana [Member] Financial Transmission Rights [Member] RTO Market Pricing [Member] Minimum [Member]	Dec. 31, 2013 Duke Energy Indiana [Member] Financial Transmission Rights [Member] RTO Market Pricing [Member] Minimum [Member]	Jun. 30, 2014 Duke Energy Indiana [Member] Financial Transmission Rights [Member] RTO Market Pricing [Member] Maximum [Member]	Dec. 31, 2013 Duke Energy Indiana [Member] Financial Transmission Rights [Member] RTO Market Pricing [Member] Maximum [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Net derivative asset (liability)	$ 22	$ (14)	$ 13	$ (87)	$ (82)	$ (85)	$ (1)	$ (2)					$ (2)			$ 45	$ 12					$ (9)	$ 23					$ 4	$ 4					$ (17)	$ (22)	$ (3)	$ (4)	$ (2)	$ (4)	$ (5)	$ (12)	$ (2)					$ (3)		$ (3)		$ (35)	$ (31)	$ (38)		$ (3)		$ (35)	$ (31)	$ (38)	$ (28)	$ (19)	$ (4)	$ (19)	$ (5)	$ (6)	$ (1)	$ (2)					$ (13)	$ 18					$ (14)	$ (20)	$ 45	$ 7	$ 12	$ 18	$ 4	$ 10	$ 45	$ 12
Fair Value Inputs Price Per MMBtu									2.92	3.07	4.71	5.37																																																								2.92	3.07	4.71	5.37
Fair value inputs, price per MWh														25.79	52.38			(4.53)	(0.30)	60.90	13.80			25.10	20.77	62.77	58.90																36.37	25.79	62.54	52.38																												25.55	20.77	65.42	58.90											(4.53)	(0.30)	60.90	13.80
Fair Value Inputs Price Per Mwd																														27.65	30.40	161.10	165.10