Summary of Significant Accounting Policies (Other Assets and Liabilities)(Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Organization And Basis Of Presentation [Line Items]
Other current receivables	$ 751	$ 515
Collateral assets		30
Current Liabilities, Other [Member]
Organization And Basis Of Presentation [Line Items]
Accrued compensation	765	619
Duke Energy Carolinas [Member]
Organization And Basis Of Presentation [Line Items]
Other current receivables	160	142
Duke Energy Carolinas [Member] | Current Liabilities, Other [Member]
Organization And Basis Of Presentation [Line Items]
Accrued compensation	248	213
Collateral liabilities	155	141
Progress Energy [Member]
Organization And Basis Of Presentation [Line Items]
Other current receivables	114	151
Collateral assets		30
Progress Energy [Member] | Current Assets, Other [Member]
Organization And Basis Of Presentation [Line Items]
Income taxes receivable	19	129
Progress Energy [Member] | Current Liabilities, Other [Member]
Organization And Basis Of Presentation [Line Items]
Customer deposits	363	373
Derivative liabilities	1	201
Duke Energy Progress [Member]
Organization And Basis Of Presentation [Line Items]
Other current receivables	51	87
Duke Energy Progress [Member] | Current Assets, Other [Member]
Organization And Basis Of Presentation [Line Items]
Income taxes receivable	16	111
Duke Energy Progress [Member] | Current Liabilities, Other [Member]
Organization And Basis Of Presentation [Line Items]
Customer deposits	141	141
Accrued compensation	135	108
Derivative liabilities		76
Duke Energy Florida [Member]
Organization And Basis Of Presentation [Line Items]
Other current receivables	61	60
Collateral assets		30
Duke Energy Florida [Member] | Current Liabilities, Other [Member]
Organization And Basis Of Presentation [Line Items]
Customer deposits	222	232
Derivative liabilities	1	125
Duke Energy Ohio [Member]
Organization And Basis Of Presentation [Line Items]
Other current receivables	71	66
Duke Energy Ohio [Member] | Current Assets, Other [Member]
Organization And Basis Of Presentation [Line Items]
Income taxes receivable	16	59
Other current receivables		33
Duke Energy Ohio [Member] | Current Liabilities, Other [Member]
Organization And Basis Of Presentation [Line Items]
Accrued litigation reserve	4	80
Collateral liabilities	62	48
Duke Energy Indiana [Member]
Organization And Basis Of Presentation [Line Items]
Other current receivables	105	96
Duke Energy Indiana [Member] | Current Liabilities, Other [Member]
Organization And Basis Of Presentation [Line Items]
Collateral liabilities	$ 44	$ 44