Business Segments (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]
Interest Expense	$ 405	$ 378	$ 1,212	$ 1,125
Progress Energy [Member]
Segment Reporting Information [Line Items]
Interest Expense	166	162	502	520
Duke Energy Ohio [Member]
Segment Reporting Information [Line Items]
Interest Expense	20	14	60	47
Other [Member] | Progress Energy [Member]
Segment Reporting Information [Line Items]
Interest Expense	$ 58	$ 64	$ 181	$ 235
National Methanol Company [Member] | International Energy [Member]
Segment Reporting Information [Line Items]
Equity Method Investment, Ownership Percentage	25.00%		25.00%