Acquisitions and Sales of Other Assets (Accounting Charges) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Significant Acquisitions and Disposals [Line Items]
Severance charges	$ 34	[1]	$ 201	[1]
FERC mitigation			117
Community support and charitable contributions and other	34		92
Progress Merger [Member]
Significant Acquisitions and Disposals [Line Items]
Severance charges			196
FERC mitigation			117
Community support and charitable contributions and other			169
Total charges related to the merger consummation			482
Duke Energy Carolinas [Member]
Significant Acquisitions and Disposals [Line Items]
Severance charges	8		63
FERC mitigation			46
Community support and charitable contributions and other	14		56
Duke Energy Carolinas [Member] | Progress Merger [Member]
Significant Acquisitions and Disposals [Line Items]
Severance charges			63
FERC mitigation			46
Community support and charitable contributions and other			79
Total charges related to the merger consummation			188
Progress Energy [Member]
Significant Acquisitions and Disposals [Line Items]
Severance charges	19		82
FERC mitigation	0		71		0
Community support and charitable contributions and other	20		36		0
Progress Energy [Member] | Progress Merger [Member]
Significant Acquisitions and Disposals [Line Items]
Severance charges			82
FERC mitigation			71
Community support and charitable contributions and other			74
Total charges related to the merger consummation			227
Duke Energy Progress [Member]
Significant Acquisitions and Disposals [Line Items]
Severance charges	14		55
FERC mitigation	0		71		0
Community support and charitable contributions and other	20		36		0
Duke Energy Progress [Member] | Progress Merger [Member]
Significant Acquisitions and Disposals [Line Items]
Severance charges			55
FERC mitigation			71
Community support and charitable contributions and other			63
Total charges related to the merger consummation			189
Duke Energy Florida [Member]
Significant Acquisitions and Disposals [Line Items]
Severance charges	5		27
Duke Energy Florida [Member] | Progress Merger [Member]
Significant Acquisitions and Disposals [Line Items]
Severance charges			27
Community support and charitable contributions and other			11
Total charges related to the merger consummation			38
Duke Energy Ohio [Member]
Significant Acquisitions and Disposals [Line Items]
Severance charges	2		21
Duke Energy Ohio [Member] | Progress Merger [Member]
Significant Acquisitions and Disposals [Line Items]
Severance charges			21
Community support and charitable contributions and other			7
Total charges related to the merger consummation			28
Duke Energy Indiana [Member]
Significant Acquisitions and Disposals [Line Items]
Severance charges	2		18
Duke Energy Indiana [Member] | Progress Merger [Member]
Significant Acquisitions and Disposals [Line Items]
Severance charges			18
Community support and charitable contributions and other			6
Total charges related to the merger consummation			$ 24

[1] Includes $5 million and $14 million of accelerated stock award expense and $2 million and $19 million of COBRA and healthcare reimbursement expenses for 2013 and 2012, respectively.