Variable Interest Entities (Consolidated VIEs) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011	Dec. 31, 2010
Variable Interest Entity Consolidated Carrying Amount Assets [Abstract]
Cash and cash equivalents	$ 1,501		$ 1,424		$ 2,110	$ 1,670
Restricted receivables of VIEs	1,719		1,201
Other current assets	1,821		1,688
Investments and other assets	3,539		2,904
Accumulated depreciation and amortization	(33,625)		(31,969)
Other deferred debits	181		178
Variable Interest Entity Consolidated Carrying Amount Liabilities [Abstract]
Accounts payable	2,391		2,444
Notes payable and commercial paper	839		1,057
Current maturities of long-term debt	2,104		3,110
Other current liabilities	2,003		2,355
Long-term debt	38,152		36,351
Deferred income taxes	12,097		10,490
Asset retirement obligation	4,950		5,169
Other liabilities	1,815		2,221
Noncontrolling interests	78		78
Cinergy Receivables [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount Assets [Abstract]
Restricted receivables of VIEs	595		534
Total assets	595		534
Variable Interest Entity Consolidated Carrying Amount Liabilities [Abstract]
Notes payable and commercial paper			312
Long-term debt	325	[1]
Total liabilities	325		312
Net assets of consolidated VIEs	270		222
CinCap V [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount Assets [Abstract]
Restricted receivables of VIEs	17		15
Other current assets	10		4
Investments and other assets	51		62
Total assets	78		81
Variable Interest Entity Consolidated Carrying Amount Liabilities [Abstract]
Current maturities of long-term debt	14		13
Other current liabilities	10		4
Long-term debt	34	[1]	48	[1]
Other liabilities	13		10
Total liabilities	71		75
Net assets of consolidated VIEs	7		6
Renewables [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount Assets [Abstract]
Restricted receivables of VIEs	18		16
Other current assets	89		133
Investments and other assets	29		14
Property, plant and equipment, cost	1,662	[2]	1,543	[2]
Accumulated depreciation and amortization	(170)		(98)
Other deferred debits	34		40
Total assets	1,662		1,648
Variable Interest Entity Consolidated Carrying Amount Liabilities [Abstract]
Accounts payable	2		1
Taxes accrued	10		62
Current maturities of long-term debt	66		459
Other current liabilities	17		25
Long-term debt	907	[1]	504	[1]
Deferred income taxes			154
Asset retirement obligation			23
Other liabilities	333		39
Total liabilities	1,335		1,267
Net assets of consolidated VIEs	327		381
Other VIEs [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount Assets [Abstract]
Restricted receivables of VIEs			(1)
Other current assets	2		2
Investments and other assets			2
Property, plant and equipment, cost	18	[2]	15	[2]
Accumulated depreciation and amortization	(5)		(5)
Other deferred debits	0
Total assets	15		13
Variable Interest Entity Consolidated Carrying Amount Liabilities [Abstract]
Net assets of consolidated VIEs	15		13
Total Consolidated VIE [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount Assets [Abstract]
Restricted receivables of VIEs	1,719		1,201
Other current assets	101		139
Investments and other assets	80		78
Property, plant and equipment, cost	1,680	[2]	1,558	[2]
Accumulated depreciation and amortization	(175)		(103)
Other deferred debits	36		40
Total assets	3,441		2,913
Variable Interest Entity Consolidated Carrying Amount Liabilities [Abstract]
Accounts payable	2		1
Notes payable and commercial paper			312
Taxes accrued	10		62
Current maturities of long-term debt	80		472
Other current liabilities	27		29
Long-term debt	1,966	[1]	852	[1]
Deferred income taxes			154
Asset retirement obligation			23
Other liabilities	347		49
Total liabilities	2,432		1,954
Net assets of consolidated VIEs	1,009		959
Duke Energy Carolinas [Member]
Variable Interest Entity Consolidated Carrying Amount Assets [Abstract]
Cash and cash equivalents	23		19		289	153
Restricted receivables of VIEs	673		637
Other current assets	309		218
Investments and other assets	1,000		934
Accumulated depreciation and amortization	(11,894)		(11,437)
Other deferred debits	46		71
Variable Interest Entity Consolidated Carrying Amount Liabilities [Abstract]
Accounts payable	701		599
Current maturities of long-term debt	47		406
Other current liabilities	393		412
Long-term debt	8,089		8,035
Deferred income taxes	5,706		5,181
Asset retirement obligation	1,594		1,959
Other liabilities	676		924
Duke Energy Carolinas [Member] | DERF [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount Assets [Abstract]
Restricted receivables of VIEs	673	[3]	637	[3]
Other deferred debits	1	[3]
Total assets	674	[3]	637	[3]
Variable Interest Entity Consolidated Carrying Amount Liabilities [Abstract]
Long-term debt	400	[1],[3]	300	[1],[3]
Other liabilities	1	[3]
Total liabilities	401	[3]	300	[3]
Net assets of consolidated VIEs	273	[3]	337	[3]
Duke Energy Progress [Member]
Variable Interest Entity Consolidated Carrying Amount Assets [Abstract]
Cash and cash equivalents	21		18		20	230
Restricted receivables of VIEs	417		0
Other current assets	296		236
Investments and other assets	443		251
Accumulated depreciation and amortization	(8,623)		(8,185)
Other deferred debits	32		29
Variable Interest Entity Consolidated Carrying Amount Liabilities [Abstract]
Accounts payable	420		542
Current maturities of long-term debt	174		407
Other current liabilities	392		507
Long-term debt	5,061		4,433
Deferred income taxes	2,557		2,162
Asset retirement obligation	1,729		1,649
Other liabilities	222		387
Duke Energy Progress [Member] | DEPR [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount Assets [Abstract]
Restricted receivables of VIEs	416	[4]
Other deferred debits	1	[4]
Total assets	417	[4]
Variable Interest Entity Consolidated Carrying Amount Liabilities [Abstract]
Long-term debt	300	[1],[4]
Total liabilities	300	[4]
Net assets of consolidated VIEs	$ 117	[4]

[1] Non-recourse to the general assets of Duke Energy.

[2] Restricted as collateral for non-recourse debt of VIEs.

[3] DERF is consolidated by Duke Energy Carolinas and Duke Energy.

[4] DEPR is consolidated by Duke Energy Progress and Duke Energy.