Employee Benefit Plans (Fair Value Measurements of Plan Assets - Master Retirement Trust) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Master Trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 8,261	[1]	$ 5,230	[2]
Master Trust [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	2,120	[1]	1,421	[2]
Master Trust [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	5,595	[1]	3,457	[2]
Master Trust [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	546	[1]	352	[2]
Master Trust [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	2,877		2,993
Master Trust [Member] | Equity Securities [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	1,801		1,415
Master Trust [Member] | Equity Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	1,022		1,575
Master Trust [Member] | Equity Securities [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	54		3
Master Trust [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	2,604		1,391
Master Trust [Member] | Corporate Debt Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	2,601		1,388
Master Trust [Member] | Corporate Debt Securities [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	3		3
Master Trust [Member] | Short Term Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	1,158		100
Master Trust [Member] | Short Term Investments [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	254		23
Master Trust [Member] | Short Term Investments [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	904		77
Master Trust [Member] | Partnership Interest [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	307		141
Master Trust [Member] | Partnership Interest [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	307		141
Master Trust [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	164		97
Master Trust [Member] | Hedge Funds [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	111		97
Master Trust [Member] | Hedge Funds [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	53
Master Trust [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	95		167
Master Trust [Member] | Real Estate [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	95		167
Master Trust [Member] | US Treasury and Government [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	927		237
Master Trust [Member] | US Treasury and Government [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	927		237
Master Trust [Member] | Guaranteed Investment Contracts [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	33		37
Master Trust [Member] | Guaranteed Investment Contracts [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	33		37
Master Trust [Member] | Government Bonds - Foreign [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	19		65
Master Trust [Member] | Government Bonds - Foreign [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	18		64
Master Trust [Member] | Government Bonds - Foreign [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	1		1
Master Trust [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	58		4
Master Trust [Member] | Cash and Cash Equivalents [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	58		4
Master Trust [Member] | Asset Backed Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	7		14
Master Trust [Member] | Asset Backed Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	7		14
Master Trust [Member] | Miscellaneous Investments And Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	12		(16)
Master Trust [Member] | Miscellaneous Investments And Other [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	7		(21)
Master Trust [Member] | Miscellaneous Investments And Other [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	5		5
VEBA I [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	51		50
VEBA I [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	51		50
VEBA I [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	15		12
VEBA I [Member] | Equity Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	15		12
VEBA I [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	21		22
VEBA I [Member] | Cash and Cash Equivalents [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	21		22
VEBA I [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	15		16
VEBA I [Member] | Debt Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets	15		16
Duke Energy Carolinas [Member] | Master Trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Allocated assets	28.00%		43.00%
Progress Energy [Member] | Master Trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			2,690	[3]
Allocated assets	35.00%
Progress Energy [Member] | Master Trust [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			879	[3]
Progress Energy [Member] | Master Trust [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			1,523	[3]
Progress Energy [Member] | Master Trust [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			288	[3]
Progress Energy [Member] | Master Trust [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			1,094
Progress Energy [Member] | Master Trust [Member] | Equity Securities [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			361
Progress Energy [Member] | Master Trust [Member] | Equity Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			733
Progress Energy [Member] | Master Trust [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			432
Progress Energy [Member] | Master Trust [Member] | Corporate Debt Securities [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			432
Progress Energy [Member] | Master Trust [Member] | Partnership Interest [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			154
Progress Energy [Member] | Master Trust [Member] | Partnership Interest [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			154
Progress Energy [Member] | Master Trust [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			313
Progress Energy [Member] | Master Trust [Member] | Hedge Funds [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			189
Progress Energy [Member] | Master Trust [Member] | Hedge Funds [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			124
Progress Energy [Member] | Master Trust [Member] | US Treasury and Government [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			515
Progress Energy [Member] | Master Trust [Member] | US Treasury and Government [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			405
Progress Energy [Member] | Master Trust [Member] | US Treasury and Government [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			110
Progress Energy [Member] | Master Trust [Member] | Government Bonds - Foreign [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			6
Progress Energy [Member] | Master Trust [Member] | Government Bonds - Foreign [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			6
Progress Energy [Member] | Master Trust [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			160
Progress Energy [Member] | Master Trust [Member] | Cash and Cash Equivalents [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			113
Progress Energy [Member] | Master Trust [Member] | Cash and Cash Equivalents [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			47
Progress Energy [Member] | Master Trust [Member] | Miscellaneous Investments And Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			16
Progress Energy [Member] | Master Trust [Member] | Miscellaneous Investments And Other [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			6
Progress Energy [Member] | Master Trust [Member] | Miscellaneous Investments And Other [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets			$ 10
Duke Energy Progress [Member] | Master Trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Allocated assets	16.00%		48.00%
Duke Energy Florida [Member] | Master Trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Allocated assets	16.00%		44.00%
Duke Energy Ohio [Member] | Master Trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Allocated assets	5.00%		9.00%
Duke Energy Indiana [Member] | Master Trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Allocated assets	8.00%		12.00%

[1] Duke Energy Carolinas, Progress Energy, Duke Energy Progress, Duke Energy Florida, Duke Energy Ohio and Duke Energy Indiana were allocated approximately 28 percent, 35 percent, 16 percent, 16 percent, 5 percent and 8 percent, respectively, of the Duke Energy Master Retirement Trust assets at December 31, 2013. Accordingly, all Level 1, 2 and 3 amounts included in the table above are allocable to the Subsidiary Registrants using these percentages.

[2] Duke Energy Carolinas, Duke Energy Ohio and Duke Energy Indiana were allocated approximately 43 percent, 9 percent and 12 percent, respectively, of the Duke Energy Master Retirement Trust assets at December 31, 2012. Accordingly, all Level 1, 2 and 3 amounts included in the table above are allocable to Duke Energy Carolinas, Duke Energy Ohio and Duke Energy Indiana using these percentages.

[3] Duke Energy Progress and Duke Energy Florida were allocated approximately 48 percent and 44 percent, respectively, of the Progress Energy Master Trust assets at December 31, 2012. Accordingly, all Level 1, 2 and 3 amounts included in the table above are allocable to Duke Energy Progress and Duke Energy Florida using these percentages.