Acquisitions and Dispositions (Narrative) (Details) (USD $)	9 Months Ended			12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2014 Scenario Forecast [Member] Duke Energy Ohio [Member] Midwest Generation Business [Member]	Dec. 31, 2016 Scenario Forecast [Member] Duke Energy Progress [Member] NCEMPA Generating Assets [Member]
Significant Acquisitions and Disposals [Line Items]
Payments to acquire businesses	$ 16,000,000			$ 1,200,000,000
Disposal Group, Including Discontinued Operation, Consideration			$ 2,800,000,000