Commitments and Contingencies (Schedule of Environmental Loss Contingencies)(Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	$ 94	$ 92	$ 74
Provision/adjustments	19	11	32
Cash reductions	(15)	(9)	(14)
Ending balance	98	94	92
Duke Energy Carolinas [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	10	10	11
Provision/adjustments	4	1	(1)
Cash reductions	(4)	(1)
Ending balance	10	10	10
Progress Energy [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	17	17	27
Provision/adjustments	7	4	1
Cash reductions	(6)	(4)	(11)
Ending balance	18	17	17
Duke Energy Progress [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	3	5	8
Provision/adjustments	2		4
Cash reductions	(2)	(2)	(7)
Ending balance	3	3	5
Duke Energy Florida [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	14	12	19
Provision/adjustments	4	4	(3)
Cash reductions	(4)	(2)	(4)
Ending balance	14	14	12
Duke Energy Ohio [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	54	54	27
Provision/adjustments	7	1	28
Cash reductions	(2)	(1)	(1)
Ending balance	59	54	54
Duke Energy Indiana [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	12	10	7
Provision/adjustments	1	5	4
Cash reductions	(3)	(3)	(1)
Ending balance	10	$ 12	$ 10
Environmental Reserves [Member]
Disclosure Environmental Matters Details [Line Items]
Environmental Exit Costs, Reasonably Possible Additional Loss	69
Environmental Reserves [Member] | Duke Energy Carolinas [Member]
Disclosure Environmental Matters Details [Line Items]
Environmental Exit Costs, Reasonably Possible Additional Loss	22
Environmental Reserves [Member] | Duke Energy Ohio [Member]
Disclosure Environmental Matters Details [Line Items]
Environmental Exit Costs, Reasonably Possible Additional Loss	36
Environmental Reserves [Member] | Duke Energy Indiana [Member]
Disclosure Environmental Matters Details [Line Items]
Environmental Exit Costs, Reasonably Possible Additional Loss	$ 7