Other Income and Expenses, Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Component Of Other Income Expense Nonoperating [Line Items]
Interest income	$ 21	$ 20	$ 16
AFUDC equity	200	164	135
Post in-service equity returns	67	73	89
Nonoperating income (expense), other	36	33	80
Other income and expenses, net	324	290	320
Duke Energy Carolinas [Member]
Component Of Other Income Expense Nonoperating [Line Items]
Interest income	4	2	4
AFUDC equity	102	96	91
Post in-service equity returns	55	60	71
Nonoperating income (expense), other	1	2	6
Other income and expenses, net	162	160	172
Progress Energy [Member]
Component Of Other Income Expense Nonoperating [Line Items]
Interest income	4	4	3
AFUDC equity	76	54	26
Post in-service equity returns	12	13	17
Nonoperating income (expense), other	22	26	31
Other income and expenses, net	114	97	77
Duke Energy Progress [Member]
Component Of Other Income Expense Nonoperating [Line Items]
Interest income	3	2
AFUDC equity	50	47	25
Post in-service equity returns	12	13	17
Nonoperating income (expense), other	6	9	9
Other income and expenses, net	71	71	51
Duke Energy Florida [Member]
Component Of Other Income Expense Nonoperating [Line Items]
Interest income	2	2	2
AFUDC equity	26	7
Nonoperating income (expense), other	16	15	18
Other income and expenses, net	44	24	20
Duke Energy Ohio [Member]
Component Of Other Income Expense Nonoperating [Line Items]
Interest income	5	4	8
AFUDC equity	6	3	4
Nonoperating income (expense), other	(2)	(1)	(2)
Other income and expenses, net	9	6	10
Duke Energy Indiana [Member]
Component Of Other Income Expense Nonoperating [Line Items]
Interest income	6	6	6
AFUDC equity	16	11	14
Nonoperating income (expense), other		(6)	2
Other income and expenses, net	$ 22	$ 11	$ 22