An estimate of the change against earnings in future periods for known and estimated costs of termination benefits provided to current employees that are involuntarily terminated under a benefit arrangement associated with exit from or disposal of business activities or restructurings pursuant to a duly authorized plan, excluding costs or losses pertaining to an entity newly acquired in a business combination or a discontinued operation as defined by generally accepted accounting principles and costs associated with one-time termination benefits.

No definition available.

Name:	duk_EsimatedSeveranceExpense
Namespace Prefix:	duk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Severance (Narrative)(Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				12 Months Ended
	Mar. 31, 2013 2011 Severance Plan [Member]	Mar. 31, 2012 2011 Severance Plan [Member] Employees	Mar. 31, 2013 Duke Energy Ohio Union 2012 Severance Plan [Member] Employees	Mar. 31, 2013 Crystal River Unit 3 2013 Severance Plan [Member]	Dec. 31, 2014 Crystal River Unit 3 2013 Severance Plan [Member] Employees
Restructuring Cost and Reserve [Line Items]
Number of employees that accepted the termination benefits		1,100	75
Number of eligible employees					600
Estimated severance expense	$ 20
Deferred severance costs				$ 16