Commitments and Contingencies (PurchPower)(Details) (Public Utilities Purchased Power [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Duke Energy Progress [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, share of plant output being purchased	100.00%
2014	$ 36	[1]
2015	36	[1]
2016	36	[1]
2017	37	[1]
2018	37	[1]
Thereafter	69	[1]
Total	251	[1]
Duke Energy Progress [Member] | Maximum [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, date of contract expiration	2022
Duke Energy Progress [Member] | Minimum [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, date of contract expiration	2019
Duke Energy Florida [Member]
Unconditional Purchase Obligations [Abstract]
2014	288	[2]
2015	295	[2]
2016	295	[2]
2017	288	[2]
2018	303	[2]
Thereafter	2,139	[2]
Total	3,608	[2]
Duke Energy Florida [Member] | Maximum [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, date of contract expiration	2025
Long-term contract for purchase of electric power, share of plant output being purchased	100.00%
Duke Energy Florida [Member] | Minimum [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, date of contract expiration	2014
Long-term contract for purchase of electric power, share of plant output being purchased	2.00%
Duke Energy Ohio [Member]
Unconditional Purchase Obligations [Abstract]
2014	250	[3]
2015	97	[3]
Total	$ 347	[3]
Duke Energy Ohio [Member] | Maximum [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, date of contract expiration	2015
Long-term contract for purchase of electric power, share of plant output being purchased	24.00%
Duke Energy Ohio [Member] | Minimum [Member]
Unconditional Purchase Obligations [Abstract]
Long-term contract for purchase of electric power, date of contract expiration	2014
Long-term contract for purchase of electric power, share of plant output being purchased	1.00%

[1] Contracts represent 100 percent of net plant output.

[2] Contracts represent between 2 percent and 100 percent of net plant output.

[3] Contracts represent between 1 percent and 24 percent of net plant output.