Asset Retirement Obligations (Recorded on the Balance Sheet) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	$ 10,611	$ 10,249	$ 8,464
Asset Retirement Obligation, Current	411
Asset Retirement Obligations, Noncurrent	10,200	10,249
Decommissioning of Nuclear Power Facilities [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	5,204
Closure of Ash Impoundments [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	5,150
Other [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	257
Duke Energy Carolinas [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	3,895	3,918	3,428
Asset Retirement Obligation, Current	222
Asset Retirement Obligations, Noncurrent	3,673	3,918
Duke Energy Carolinas [Member] | Decommissioning of Nuclear Power Facilities [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	1,834
Duke Energy Carolinas [Member] | Closure of Ash Impoundments [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	2,032
Duke Energy Carolinas [Member] | Other [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	29
Progress Energy [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	5,475	5,369	4,711
Asset Retirement Obligation, Current	189
Asset Retirement Obligations, Noncurrent	5,286	5,369
Progress Energy [Member] | Decommissioning of Nuclear Power Facilities [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	3,172
Progress Energy [Member] | Closure of Ash Impoundments [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	2,228
Progress Energy [Member] | Other [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	75
Duke Energy Progress [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	4,697	4,567	3,905
Asset Retirement Obligation, Current	189
Asset Retirement Obligations, Noncurrent	4,508	4,567
Duke Energy Progress [Member] | Decommissioning of Nuclear Power Facilities [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	2,454
Duke Energy Progress [Member] | Closure of Ash Impoundments [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	2,209
Duke Energy Progress [Member] | Other [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	34
Duke Energy Florida [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	778	802	806
Asset Retirement Obligations, Noncurrent	778	802
Duke Energy Florida [Member] | Decommissioning of Nuclear Power Facilities [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	717
Duke Energy Florida [Member] | Closure of Ash Impoundments [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	19
Duke Energy Florida [Member] | Other [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	42
Duke Energy Ohio [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	77	125	27
Asset Retirement Obligations, Noncurrent	77	125
Duke Energy Ohio [Member] | Closure of Ash Impoundments [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	43
Duke Energy Ohio [Member] | Other [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	34
Duke Energy Indiana [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	866	525	$ 32
Asset Retirement Obligations, Noncurrent	866	$ 525
Duke Energy Indiana [Member] | Closure of Ash Impoundments [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	847
Duke Energy Indiana [Member] | Other [Member]
Asset Retirement Obligation [Line Items]
Asset Retirement Obligation	$ 19