Commitments and Contingencies (Future Minimum Payments for Operating and Capital Leases) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Leased Assets
Rental expense on operating leases	$ 242	$ 313	$ 350
Operating Leases, Future Minimum Payments Due [Abstract]
2017	218
2018	205
2019	181
2020	164
2021	134
Thereafter	948
Total future minimum lease payments	1,850
Capital Leases, Future Minimum Payments Due [Abstract]
2017	148
2018	154
2019	154
2020	159
2021	163
Thereafter	784
Minimum annual payments	1,562
Less amount representing interest	(462)
Total	1,100
Duke Energy Carolinas [Member]
Operating Leased Assets
Rental expense on operating leases	45	41	41
Operating Leases, Future Minimum Payments Due [Abstract]
2017	41
2018	35
2019	27
2020	23
2021	17
Thereafter	52
Total future minimum lease payments	195
Capital Leases, Future Minimum Payments Due [Abstract]
2017	6
2018	6
2019	6
2020	5
2021	1
Thereafter	30
Minimum annual payments	54
Less amount representing interest	(32)
Total	22
Progress Energy [Member]
Operating Leased Assets
Rental expense on operating leases	140	230	257
Operating Leases, Future Minimum Payments Due [Abstract]
2017	129
2018	126
2019	120
2020	109
2021	91
Thereafter	602
Total future minimum lease payments	1,177
Capital Leases, Future Minimum Payments Due [Abstract]
2017	46
2018	46
2019	45
2020	46
2021	45
Thereafter	322
Minimum annual payments	550
Less amount representing interest	(265)
Total	285
Duke Energy Progress [Member]
Operating Leased Assets
Rental expense on operating leases	68	149	161
Operating Leases, Future Minimum Payments Due [Abstract]
2017	75
2018	73
2019	68
2020	58
2021	43
Thereafter	379
Total future minimum lease payments	696
Capital Leases, Future Minimum Payments Due [Abstract]
2017	21
2018	21
2019	20
2020	22
2021	20
Thereafter	250
Minimum annual payments	354
Less amount representing interest	(212)
Total	142
Duke Energy Florida [Member]
Operating Leased Assets
Rental expense on operating leases	72	81	96
Operating Leases, Future Minimum Payments Due [Abstract]
2017	54
2018	53
2019	52
2020	51
2021	48
Thereafter	223
Total future minimum lease payments	481
Capital Leases, Future Minimum Payments Due [Abstract]
2017	25
2018	25
2019	25
2020	25
2021	25
Thereafter	71
Minimum annual payments	196
Less amount representing interest	(53)
Total	143
Duke Energy Ohio [Member]
Operating Leased Assets
Rental expense on operating leases	16	13	17
Operating Leases, Future Minimum Payments Due [Abstract]
2017	12
2018	11
2019	7
2020	6
2021	4
Thereafter	7
Total future minimum lease payments	47
Capital Leases, Future Minimum Payments Due [Abstract]
2017	4
2018	3
2019	1
Minimum annual payments	8
Less amount representing interest	(1)
Total	7
Duke Energy Indiana [Member]
Operating Leased Assets
Rental expense on operating leases	23	$ 20	$ 21
Operating Leases, Future Minimum Payments Due [Abstract]
2017	20
2018	17
2019	11
2020	10
2021	6
Thereafter	9
Total future minimum lease payments	73
Capital Leases, Future Minimum Payments Due [Abstract]
2017	1
2018	2
2019	1
2020	1
2021	1
Thereafter	41
Minimum annual payments	47
Less amount representing interest	(36)
Total	$ 11