Fair Value Measurements (Quantitative Level 3 Fair Value Disclosure) (Details) (USD $) In Millions, unless otherwise specified							12 Months Ended						12 Months Ended						12 Months Ended						12 Months Ended					12 Months Ended				12 Months Ended										12 Months Ended								12 Months Ended			12 Months Ended						12 Months Ended			12 Months Ended								12 Months Ended					12 Months Ended				12 Months Ended												12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2013 Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member]	Dec. 31, 2012 Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member]	Dec. 31, 2013 Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member] Maximum [Member]	Dec. 31, 2012 Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member] Maximum [Member]	Dec. 31, 2013 Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2012 Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2013 FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member]	Dec. 31, 2012 FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member]	Dec. 31, 2013 FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member] Maximum [Member]	Dec. 31, 2012 FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member] Maximum [Member]	Dec. 31, 2013 FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2012 FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2013 Financial Transmission Rights [Member] RTO Market Pricing [Member]	Dec. 31, 2012 Financial Transmission Rights [Member] RTO Market Pricing [Member]	Dec. 31, 2013 Financial Transmission Rights [Member] RTO Market Pricing [Member] Maximum [Member]	Dec. 31, 2012 Financial Transmission Rights [Member] RTO Market Pricing [Member] Maximum [Member]	Dec. 31, 2013 Financial Transmission Rights [Member] RTO Market Pricing [Member] Minimum [Member]	Dec. 31, 2012 Financial Transmission Rights [Member] RTO Market Pricing [Member] Minimum [Member]	Dec. 31, 2013 Commodity Power Contracts [Member] Discounted Cash Flow [Member]	Dec. 31, 2012 Commodity Power Contracts [Member] Discounted Cash Flow [Member]	Dec. 31, 2013 Commodity Power Contracts [Member] Discounted Cash Flow [Member] Maximum [Member]	Dec. 31, 2012 Commodity Power Contracts [Member] Discounted Cash Flow [Member] Maximum [Member]	Dec. 31, 2013 Commodity Power Contracts [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2012 Commodity Power Contracts [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2012 Commodity Capacity Contracts [Member] Discounted Cash Flow [Member]	Dec. 31, 2012 Commodity Capacity Contracts [Member] Discounted Cash Flow [Member] Maximum [Member]	Dec. 31, 2012 Commodity Capacity Contracts [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2013 Commodity Capacity Option Contracts [Member] Discounted Cash Flow [Member]	Dec. 31, 2012 Commodity Capacity Option Contracts [Member] Discounted Cash Flow [Member]	Dec. 31, 2013 Commodity Capacity Option Contracts [Member] Discounted Cash Flow [Member] Maximum [Member]	Dec. 31, 2012 Commodity Capacity Option Contracts [Member] Discounted Cash Flow [Member] Maximum [Member]	Dec. 31, 2013 Commodity Capacity Option Contracts [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2012 Commodity Capacity Option Contracts [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2013 Derivative Financial Instruments Liabilities Reserves [Member]	Dec. 31, 2012 Derivative Financial Instruments Liabilities Reserves [Member]	Dec. 31, 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]	Dec. 31, 2012 Duke Energy Carolinas [Member] FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member]	Dec. 31, 2013 Duke Energy Carolinas [Member] FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member] Maximum [Member]	Dec. 31, 2012 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] Minimum [Member]	Dec. 31, 2012 Duke Energy Carolinas [Member] FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2012 Progress Energy [Member]	Dec. 31, 2011 Progress Energy [Member]	Dec. 31, 2010 Progress Energy [Member]	Dec. 31, 2012 Progress Energy [Member] Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member]	Dec. 31, 2012 Progress Energy [Member] Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member] Maximum [Member]	Dec. 31, 2012 Progress Energy [Member] Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2012 Progress Energy [Member] FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member]	Dec. 31, 2012 Progress Energy [Member] FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member] Maximum [Member]	Dec. 31, 2012 Progress Energy [Member] FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2012 Duke Energy Progress [Member]	Dec. 31, 2011 Duke Energy Progress [Member]	Dec. 31, 2010 Duke Energy Progress [Member]	Dec. 31, 2012 Duke Energy Progress [Member] Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member]	Dec. 31, 2012 Duke Energy Progress [Member] Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member] Maximum [Member]	Dec. 31, 2012 Duke Energy Progress [Member] Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2012 Duke Energy Progress [Member] FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member]	Dec. 31, 2012 Duke Energy Progress [Member] FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member] Maximum [Member]	Dec. 31, 2012 Duke Energy Progress [Member] FERC Mitigation Power Sale Agreements [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2013 Duke Energy Ohio [Member]	Dec. 31, 2012 Duke Energy Ohio [Member]	Dec. 31, 2011 Duke Energy Ohio [Member]	Dec. 31, 2010 Duke Energy Ohio [Member]	Dec. 31, 2013 Duke Energy Ohio [Member] Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member]	Dec. 31, 2012 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] Maximum [Member]	Dec. 31, 2012 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] Minimum [Member]	Dec. 31, 2012 Duke Energy Ohio [Member] Commodity Natural Gas Hedges [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2012 Duke Energy Ohio [Member] Financial Transmission Rights [Member] RTO Market Pricing [Member]	Dec. 31, 2012 Duke Energy Ohio [Member] Financial Transmission Rights [Member] RTO Market Pricing [Member] Maximum [Member]	Dec. 31, 2012 Duke Energy Ohio [Member] Financial Transmission Rights [Member] RTO Market Pricing [Member] Minimum [Member]	Dec. 31, 2013 Duke Energy Ohio [Member] Commodity Power Contracts [Member] Discounted Cash Flow [Member]	Dec. 31, 2012 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] Maximum [Member]	Dec. 31, 2012 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] Minimum [Member]	Dec. 31, 2012 Duke Energy Ohio [Member] Commodity Power Contracts [Member] Discounted Cash Flow [Member] Minimum [Member]	Dec. 31, 2013 Duke Energy Ohio [Member] Derivative Financial Instruments Liabilities Reserves [Member]	Dec. 31, 2012 Duke Energy Ohio [Member] Derivative Financial Instruments Liabilities Reserves [Member]	Dec. 31, 2013 Duke Energy Indiana [Member]	Dec. 31, 2012 Duke Energy Indiana [Member]	Dec. 31, 2011 Duke Energy Indiana [Member]	Dec. 31, 2010 Duke Energy Indiana [Member]	Dec. 31, 2013 Duke Energy Indiana [Member] Financial Transmission Rights [Member] RTO Market Pricing [Member]	Dec. 31, 2012 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] Maximum [Member]	Dec. 31, 2012 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] Minimum [Member]	Dec. 31, 2012 Duke Energy Indiana [Member] Financial Transmission Rights [Member] RTO Market Pricing [Member] Minimum [Member]
Net Derivative Asset (Liability) Fair Value Inputs [Line Items]
Fair value inputs, price FTR																			13.80	39.22	(0.30)	23.63																																																							39.22	27.17															13.80	35.43	(0.30)	23.63
Fair value inputs, price per MWh													52.38	48.69	25.79	25.83									58.90	77.96	20.77	24.82																52.38	48.69	25.79	25.83								48.69	25.83								48.69	25.83																58.90	57.50	20.77	25.90
Fair Value Inputs Price Per MMBtu							5.37	9.99	3.07	2.33																																										4.45	4.07								4.45	4.07										5.37	4.51	3.07	3.30
Fair Value Inputs Price Per Mwd																														105.36	95.16			165.10	77.96	30.40	4.68
Net derivative asset (liability)	$ 13	$ (85)	$ (39)	$ (19)	$ (2)	$ (53)					$ (2)	$ (23)					$ 12	$ 11					$ 23	$ (8)					$ (3)			$ 4	$ 3					$ (22)	$ (12)	$ (2)	$ (12)	$ (2)	$ (12)					$ (38)	$ (24)	$ (36)	$ (27)			$ (11)			$ (38)	$ (24)	$ (36)	$ (27)			$ (11)			$ (4)	$ (6)	$ (3)	$ 13	$ (2)	$ 5					$ 1			$ 18	$ (1)					$ (20)	$ (11)	$ 12	$ 10	$ 4	$ 4	$ 12	$ 10