Income Taxes (Effective Tax Rates) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense, computed at the statutory rate of 35%	$ 1,372	$ 858	$ 863
State income tax, net of federal income tax effect	67	64	50
Tax differential on foreign earnings	(45)	(66)	(44)
AFUDC equity income	(55)	(101)	(91)
Renewable energy production tax credits	(59)	(25)	(21)
Other items, net	(19)	(25)	(5)
Income Tax Expense or Benefit from Continuing Operations	1,261	705	752
Effective tax rate	32.20%	28.80%	30.50%
State [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Net reduction in deferred tax liability	145
State [Member] | Current [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Statutory tax rate	6.90%
State [Member] | January 2014 [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Statutory tax rate	6.00%
State [Member] | January 2015 [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Statutory tax rate	5.00%
Duke Energy Carolinas [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense, computed at the statutory rate of 35%	549	461	457
State income tax, net of federal income tax effect	56	34	46
AFUDC equity income	(32)	(54)	(59)
Other items, net	21	12	28
Income Tax Expense or Benefit from Continuing Operations	594	453	472
Effective tax rate	37.80%	34.30%	36.10%
Duke Energy Carolinas [Member] | State [Member] | Current [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Statutory tax rate	6.90%
Duke Energy Carolinas [Member] | State [Member] | January 2014 [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Statutory tax rate	6.00%
Duke Energy Carolinas [Member] | State [Member] | January 2015 [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Statutory tax rate	5.00%
Progress Energy [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense, computed at the statutory rate of 35%	361	185	319
State income tax, net of federal income tax effect	31	33	39
AFUDC equity income	(18)	(37)	(36)
Other items, net	(1)	(9)	1
Income Tax Expense or Benefit from Continuing Operations	373	172	323
Effective tax rate	36.20%	32.70%	35.60%
Duke Energy Progress [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense, computed at the statutory rate of 35%	276	134	270
State income tax, net of federal income tax effect	31	1	18
AFUDC equity income	(15)	(24)	(25)
Other items, net	(4)	(1)	(7)
Income Tax Expense or Benefit from Continuing Operations	288	110	256
Effective tax rate	36.50%	28.70%	33.20%
Duke Energy Progress [Member] | State [Member] | Current [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Statutory tax rate	6.90%
Duke Energy Progress [Member] | State [Member] | January 2014 [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Statutory tax rate	6.00%
Duke Energy Progress [Member] | State [Member] | January 2015 [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Statutory tax rate	5.00%
Duke Energy Florida [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense, computed at the statutory rate of 35%	188	145	173
State income tax, net of federal income tax effect	20	14	17
AFUDC equity income	(3)	(13)	(11)
Other items, net	8	1	1
Income Tax Expense or Benefit from Continuing Operations	213	147	180
Effective tax rate	39.60%	35.70%	36.30%
Duke Energy Ohio [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense, computed at the statutory rate of 35%	62	96	102
State income tax, net of federal income tax effect	2	1	(1)
AFUDC equity income	0	(2)	(2)
Other items, net	11	3	(3)
Income Tax Expense or Benefit from Continuing Operations	75	98	96
Effective tax rate	42.20%	36.00%	33.10%
Duke Energy Indiana [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Income tax expense, computed at the statutory rate of 35%	203	(43)	85
State income tax, net of federal income tax effect	23	1	13
AFUDC equity income	(5)	(26)	(31)
Other items, net	2	(5)	7
Income Tax Expense or Benefit from Continuing Operations	$ 223	$ (73)	$ 74
Effective tax rate	38.40%	59.50%	30.60%