Business Segments (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Segment Reporting Information [Line Items]
Interest Expense	$ 413	$ 381	$ 819	$ 748
Progress Energy [Member]
Segment Reporting Information [Line Items]
Interest Expense	167	160	336	358
Duke Energy Ohio [Member]
Segment Reporting Information [Line Items]
Interest Expense	29	18	51	36
Other Segments [Member] | Progress Energy [Member]
Segment Reporting Information [Line Items]
Interest Expense	$ 60	$ 70	$ 123	$ 171