Risk Management, Derivative Instruments And Hedging Activities (Notional Amounts Of Derivative Instruments Related To Interest Rate Risk) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Derivative [Line Items]
Cash Flow Hedges	$ 1,047	[1]	$ 841	[1]
Undesignated Contracts	290		247
Fair Value Hedges	250		275
Total Notional Amount	1,587		1,363
Non Recourse Long Term Debt Of Variable Interest Entities	852		949
Duke Energy Carolinas [Member]
Derivative [Line Items]
Fair Value Hedges			25
Total Notional Amount			25
Non Recourse Long Term Debt Of Variable Interest Entities	300		300
Progress Energy [Member]
Derivative [Line Items]
Cash Flow Hedges			500
Undesignated Contracts	50
Total Notional Amount	50		500
Progress Energy Carolinas [Member]
Derivative [Line Items]
Cash Flow Hedges			250
Undesignated Contracts	50
Total Notional Amount	50		250
Progress Energy Florida [Member]
Derivative [Line Items]
Cash Flow Hedges			50
Total Notional Amount			50
Duke Energy Ohio [Member]
Derivative [Line Items]
Undesignated Contracts	27		27
Fair Value Hedges	250		250
Total Notional Amount	277		277
Duke Energy Indiana [Member]
Derivative [Line Items]
Undesignated Contracts	200		200
Total Notional Amount	200		200
Cash Flow Hedging [Member]
Derivative [Line Items]
Non Recourse Long Term Debt Of Variable Interest Entities	$ 620		$ 466

[1] Duke Energy includes amounts related to non-recourse variable rate long-term debt of VIEs of $620 million at December 31, 2012 and $466 million at December 31, 2011.