Commitments and Contingencies (Schedule of Environmental Loss Contingencies)(Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	$ 75	$ 61	$ 88
Provision/adjustments	26	39	6
Cash reductions	(22)	(25)	(33)
Ending balance	79	75	61
Minimum [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Estimated cost of complying with EPA Mercury and Air Toxics Standards	525
Maximum [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Estimated cost of complying with EPA Mercury and Air Toxics Standards	625
Duke Energy Carolinas [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	12	12	13
Provision/adjustments		1
Cash reductions	(1)	(1)	(1)
Ending balance	11	12	12
Duke Energy Carolinas [Member] | Minimum [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Estimated cost of complying with EPA Mercury and Air Toxics Standards	40
Duke Energy Carolinas [Member] | Maximum [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Estimated cost of complying with EPA Mercury and Air Toxics Standards	50
Duke Energy Ohio [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	15	28	50
Provision/adjustments	20	5	5
Cash reductions	(8)	(18)	(27)
Ending balance	27	15	28
Duke Energy Ohio [Member] | Minimum [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Estimated cost of complying with EPA Mercury and Air Toxics Standards	35
Duke Energy Ohio [Member] | Maximum [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Estimated cost of complying with EPA Mercury and Air Toxics Standards	50
Duke Energy Indiana [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	8	9	11
Provision/adjustments	1	3	1
Cash reductions	(2)	(4)	(3)
Ending balance	7	8	9
Duke Energy Indiana [Member] | Minimum [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Estimated cost of complying with EPA Mercury and Air Toxics Standards	425
Duke Energy Indiana [Member] | Maximum [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Estimated cost of complying with EPA Mercury and Air Toxics Standards	485
Progress Energy [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	33	23	35
Provision/adjustments	4	19	10
Cash reductions	(10)	(9)	(22)
Ending balance	27	33	23
Progress Energy [Member] | Minimum [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Estimated cost of complying with EPA Mercury and Air Toxics Standards	25
Progress Energy [Member] | Maximum [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Estimated cost of complying with EPA Mercury and Air Toxics Standards	40
Duke Energy Progress [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	14	11	12
Provision/adjustments	(1)	5	1
Cash reductions	(5)	(2)	(2)
Ending balance	8	14	11
Duke Energy Progress [Member] | Minimum [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Estimated cost of complying with EPA Mercury and Air Toxics Standards	10
Duke Energy Progress [Member] | Maximum [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Estimated cost of complying with EPA Mercury and Air Toxics Standards	15
Duke Energy Florida [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	19	12	23
Provision/adjustments	5	14	9
Cash reductions	(5)	(7)	(20)
Ending balance	19	19	12
Duke Energy Florida [Member] | Minimum [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Estimated cost of complying with EPA Mercury and Air Toxics Standards	15
Duke Energy Florida [Member] | Maximum [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Estimated cost of complying with EPA Mercury and Air Toxics Standards	$ 25