Document And Entity Information	9 Months Ended
	Sep. 30, 2011	Nov. 04, 2011
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2011
Entity Registrant Name	Duke Energy CORP
Entity Central Index Key	0001326160
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		1,332,733,321
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q3
Duke Energy Carolinas [Member]
Entity Registrant Name	Duke Energy Carolinas, LLC
Entity Central Index Key	0000030371
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Duke Energy Ohio [Member]
Entity Registrant Name	Duke Energy Ohio, Inc.
Entity Central Index Key	0000020290
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Duke Energy Indiana [Member]
Entity Registrant Name	Duke Energy Indiana, Inc.
Entity Central Index Key	0000081020
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer