Income Taxes (Other Disclosures) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits - January 1	$ 540		$ 385	$ 342
Acquisitions	0		128
Gross increases-tax positions in prior periods	0		29	49
Gross decreases-tax positions in prior periods	(231)		(4)	(18)
Gross increases-current period tax positions	0		28	16
Gross decreases - current period tax positions	0		(9)
Decreases due to settlements	(66)		(13)	(4)
Reduction due to lapse of statute of limitations	(13)		(4)
Total changes	(310)		155	43
Unrecognized Tax Benefits - December 31	230		540	385
Amount that if recognized, would affect the effective tax rate or regulatory liability	128	[1]
Amount that if recognized, would be recorded as a component of discontinued operations	8
Significant change in unrecognized tax benefits is reasonably possible, amount of unrecorded benefit	4
Income Tax Examination, Penalties and Interest Expense [Abstract]
Net interest income recognized related to income taxes	2		10	12
Income Tax Examination, Penalties and Interest Accrued [Abstract]
Interest receivable related to income taxes	0		0	8
Interest payable related to income taxes	27		7	0
Duke Energy Carolinas [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits - January 1	271		260	217
Gross increases-tax positions in prior periods	0		12	42
Gross decreases-tax positions in prior periods	(100)		0	(8)
Gross increases-current period tax positions	0		15	9
Gross decreases - current period tax positions	0		(5)
Decreases due to settlements	0		(11)	0
Total changes	(100)		11	43
Unrecognized Tax Benefits - December 31	171		271	260
Amount that if recognized, would affect the effective tax rate or regulatory liability	116	[1]
Significant change in unrecognized tax benefits is reasonably possible, amount of unrecorded benefit	4
Income Tax Examination, Penalties and Interest Expense [Abstract]
Net interest income recognized related to income taxes	2		9	5
Income Tax Examination, Penalties and Interest Accrued [Abstract]
Interest receivable related to income taxes	0		7	5
Interest payable related to income taxes	8
Progress Energy [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits - January 1	131		173	176
Gross increases-tax positions in prior periods	0		23	88
Gross decreases-tax positions in prior periods	(86)		(72)	(24)
Gross increases-current period tax positions	0		8	9
Gross decreases - current period tax positions	0		(1)	(8)
Decreases due to settlements			0	(68)
Reduction due to lapse of statute of limitations	(13)
Total changes	(99)		(42)	(3)
Unrecognized Tax Benefits - December 31	32		131	173
Amount that if recognized, would affect the effective tax rate or regulatory liability	2	[1]
Income Tax Examination, Penalties and Interest Expense [Abstract]
Net interest income recognized related to income taxes	6		0	24
Net interest expense recognized related to income taxes	0		2	0
Income Tax Examination, Penalties and Interest Accrued [Abstract]
Interest payable related to income taxes	10		17	21
Duke Energy Progress [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits - January 1	67		73	74
Gross increases-tax positions in prior periods	0		10	19
Gross decreases-tax positions in prior periods	(45)		(19)	(14)
Gross increases-current period tax positions	0		4	8
Gross decreases - current period tax positions	0		(1)	(4)
Decreases due to settlements			0	(10)
Total changes	(45)		(6)	(1)
Unrecognized Tax Benefits - December 31	22		67	73
Amount that if recognized, would affect the effective tax rate or regulatory liability	1	[1]
Income Tax Examination, Penalties and Interest Expense [Abstract]
Net interest income recognized related to income taxes	7		0	6
Net interest expense recognized related to income taxes				0
Income Tax Examination, Penalties and Interest Accrued [Abstract]
Interest payable related to income taxes	2		8	8
Duke Energy Florida [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits - January 1	44		80	99
Gross increases-tax positions in prior periods	0		12	66
Gross decreases-tax positions in prior periods	(37)		(52)	(21)
Gross increases-current period tax positions	0		4	1
Gross decreases - current period tax positions			0	(4)
Decreases due to settlements			0	(61)
Reduction due to lapse of statute of limitations	1
Total changes	(36)		(36)	(19)
Unrecognized Tax Benefits - December 31	8		44	80
Amount that if recognized, would affect the effective tax rate or regulatory liability	1	[1]
Income Tax Examination, Penalties and Interest Expense [Abstract]
Net interest income recognized related to income taxes	0		0	22
Net interest expense recognized related to income taxes	0		2	0
Income Tax Examination, Penalties and Interest Accrued [Abstract]
Interest payable related to income taxes	7		9	7
Duke Energy Ohio [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits - January 1	36		32	29
Gross increases-tax positions in prior periods	0		2	4
Gross decreases-tax positions in prior periods	(36)		0	(5)
Gross increases-current period tax positions	0		4	4
Gross decreases - current period tax positions	0		(2)
Total changes	(36)		4	3
Unrecognized Tax Benefits - December 31	0		36	32
Income Tax Examination, Penalties and Interest Expense [Abstract]
Net interest income recognized related to income taxes	4
Net interest expense recognized related to income taxes	0		0	1
Income Tax Examination, Penalties and Interest Accrued [Abstract]
Interest payable related to income taxes	0		3	3
Duke Energy Indiana [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits - January 1	32		24	21
Gross increases-tax positions in prior periods	0		6	3
Gross decreases-tax positions in prior periods	(31)		0	(3)
Gross increases-current period tax positions	0		4	3
Gross decreases - current period tax positions	0		(2)
Decreases due to settlements				0
Total changes	(31)		8	3
Unrecognized Tax Benefits - December 31	1		32	24
Amount that if recognized, would affect the effective tax rate or regulatory liability	1	[1]
Income Tax Examination, Penalties and Interest Expense [Abstract]
Net interest income recognized related to income taxes	1		2	0
Net interest expense recognized related to income taxes			0	1
Income Tax Examination, Penalties and Interest Accrued [Abstract]
Interest payable related to income taxes	$ 0		$ 1	$ 3

[1] Duke Energy, Duke Energy Carolinas, Progress Energy, Duke Energy Progress, Duke Energy Florida and Duke Energy Indiana are unable to estimate the specific amounts that would affect the effective tax rate versus the regulatory liability.