Derivatives and Hedging (Schedule of Offsetting Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	$ 162	$ 25
Net amounts presented on Balance Sheets	162	25
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	252	397
Net amounts presented on Balance Sheets	252	397
Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	111	18
Gross amounts offset	(11)	(3)
Net amounts presented on Balance Sheets	100	15
Investments And Other Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	51	7
Gross amounts offset	(2)	(4)
Net amounts presented on Balance Sheets	49	3
Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	52	269
Gross amounts offset	(11)	(22)
Net amounts presented on Balance Sheets	41	247
Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	200	128
Gross amounts offset	(2)	(16)
Net amounts presented on Balance Sheets	198	112
Duke Energy Carolinas [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	33
Net amounts presented on Balance Sheets	33
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	16	45
Net amounts presented on Balance Sheets	16	45
Duke Energy Carolinas [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	23
Net amounts presented on Balance Sheets	23
Duke Energy Carolinas [Member] | Investments And Other Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	10
Gross amounts offset	(1)
Net amounts presented on Balance Sheets	9
Duke Energy Carolinas [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized		32
Net amounts presented on Balance Sheets		32
Duke Energy Carolinas [Member] | Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	16	13
Gross amounts offset	(1)
Net amounts presented on Balance Sheets	15	13
Progress Energy [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	85	11
Net amounts presented on Balance Sheets	85	11
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	25	322
Net amounts presented on Balance Sheets	25	322
Progress Energy [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	64	7
Gross amounts offset	(11)	(2)
Net amounts presented on Balance Sheets	53	5
Progress Energy [Member] | Investments And Other Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	21	4
Gross amounts offset	(1)	(4)
Net amounts presented on Balance Sheets	20
Progress Energy [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	12	225
Gross amounts offset	(11)	(21)
Net amounts presented on Balance Sheets	1	204
Progress Energy [Member] | Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	13	97
Gross amounts offset	(1)	(15)
Net amounts presented on Balance Sheets	12	82
Duke Energy Progress [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	46	2
Net amounts presented on Balance Sheets	46	2
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	7	98
Net amounts presented on Balance Sheets	7	98
Duke Energy Progress [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	36	2
Net amounts presented on Balance Sheets	36	2
Duke Energy Progress [Member] | Investments And Other Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	10
Gross amounts offset	(1)
Net amounts presented on Balance Sheets	9
Duke Energy Progress [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized		77
Gross amounts offset		(1)
Net amounts presented on Balance Sheets		76
Duke Energy Progress [Member] | Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	7	21
Gross amounts offset	(1)
Net amounts presented on Balance Sheets	6	21
Duke Energy Florida [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	39	7
Net amounts presented on Balance Sheets	39	7
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	12	216
Net amounts presented on Balance Sheets	12	216
Duke Energy Florida [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	28	3
Gross amounts offset	(11)	(2)
Net amounts presented on Balance Sheets	17	1
Duke Energy Florida [Member] | Investments And Other Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	11	4
Gross amounts offset		(4)
Net amounts presented on Balance Sheets	11
Duke Energy Florida [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	12	145
Gross amounts offset	(11)	(20)
Net amounts presented on Balance Sheets	1	125
Duke Energy Florida [Member] | Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized		71
Gross amounts offset		(15)
Net amounts presented on Balance Sheets		56
Duke Energy Ohio [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	5	3
Net amounts presented on Balance Sheets	5	3
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	6	7
Net amounts presented on Balance Sheets	6	7
Duke Energy Ohio [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	4	3
Net amounts presented on Balance Sheets	4	3
Duke Energy Ohio [Member] | Investments And Other Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	1
Net amounts presented on Balance Sheets	1
Duke Energy Ohio [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	1	1
Net amounts presented on Balance Sheets	1	1
Duke Energy Ohio [Member] | Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	5	6
Net amounts presented on Balance Sheets	5	6
Duke Energy Indiana [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	16	7
Net amounts presented on Balance Sheets	16	7
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	2
Net amounts presented on Balance Sheets	2
Duke Energy Indiana [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	16	7
Net amounts presented on Balance Sheets	16	$ 7
Duke Energy Indiana [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	2
Net amounts presented on Balance Sheets	$ 2