Variable Interest Entities (Consolidated VIEs) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013
Variable Interest Entity Consolidated Carrying Amount Assets [Abstract]
Restricted receivables of VIEs	$ 2,118		$ 1,719
Other current assets	1,698		1,821
Investments and other assets	3,227		3,432
Accumulated depreciation and amortization	(33,977)		(33,625)
Other deferred debits	178		181
Variable Interest Entity Consolidated Carrying Amount Liabilities [Abstract]
Accounts payable	1,782		2,391
Current maturities of long-term debt	1,887		2,104
Other current liabilities	1,786		1,996
Long-term Debt	38,706		38,152
Deferred income taxes	12,014		12,097
Asset retirement obligation	5,030		4,950
Other liabilities	1,723		1,749
Duke Energy Carolinas [Member]
Variable Interest Entity Consolidated Carrying Amount Assets [Abstract]
Restricted receivables of VIEs	705		673
Other current assets	271		309
Investments and other assets	997		1,000
Accumulated depreciation and amortization	(12,304)		(11,894)
Other deferred debits	43		46
Variable Interest Entity Consolidated Carrying Amount Liabilities [Abstract]
Accounts payable	510		701
Current maturities of long-term debt	47		47
Other current liabilities	368		393
Long-term Debt	8,088		8,089
Deferred income taxes	5,781		5,706
Asset retirement obligation	1,641		1,594
Other liabilities	678		676
Duke Energy Progress [Member]
Variable Interest Entity Consolidated Carrying Amount Assets [Abstract]
Restricted receivables of VIEs	471		417
Other current assets	271		296
Investments and other assets	461		443
Accumulated depreciation and amortization	(8,828)		(8,623)
Other deferred debits	34		32
Variable Interest Entity Consolidated Carrying Amount Liabilities [Abstract]
Accounts payable	316		420
Current maturities of long-term debt	306		174
Other current liabilities	329		392
Long-term Debt	5,411		5,061
Deferred income taxes	2,715		2,557
Asset retirement obligation	1,779		1,729
Other liabilities	198		222
Duke Energy Florida [Member]
Variable Interest Entity Consolidated Carrying Amount Assets [Abstract]
Restricted receivables of VIEs	403
Other current assets	23		182
Investments and other assets	256		252
Accumulated depreciation and amortization	(4,380)		(4,252)
Other deferred debits	43		44
Variable Interest Entity Consolidated Carrying Amount Liabilities [Abstract]
Accounts payable	345		333
Current maturities of long-term debt	12		11
Other current liabilities	405		445
Long-term Debt	5,095		4,875
Deferred income taxes	1,800		1,829
Asset retirement obligation	818		833
Other liabilities	254		255
DERF [Member] | Duke Energy Carolinas [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount Assets [Abstract]
Restricted receivables of VIEs	704		673
Other deferred debits	1		1
Total assets	705		674
Variable Interest Entity Consolidated Carrying Amount Liabilities [Abstract]
Long-term Debt	400	[1]	400	[1]
Other liabilities			1
Total liabilities	400		401
Net assets of consolidated VIEs	305		273
DEPR [Member] | Duke Energy Progress [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount Assets [Abstract]
Restricted receivables of VIEs	471		416
Other deferred debits			1
Total assets	471		417
Variable Interest Entity Consolidated Carrying Amount Liabilities [Abstract]
Long-term Debt	300	[1]	300	[1]
Other liabilities
Total liabilities	300		300
Net assets of consolidated VIEs	171		117
DEFR [Member] | Duke Energy Florida [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount Assets [Abstract]
Restricted receivables of VIEs	403
Other deferred debits	1
Total assets	404
Variable Interest Entity Consolidated Carrying Amount Liabilities [Abstract]
Long-term Debt	225	[1]
Other liabilities
Total liabilities	225
Net assets of consolidated VIEs	179
Cinergy Receivables [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount Assets [Abstract]
Restricted receivables of VIEs	506		595
Other deferred debits
Total assets	506		595
Variable Interest Entity Consolidated Carrying Amount Liabilities [Abstract]
Long-term Debt	325	[1]	325	[1]
Total liabilities	325		325
Net assets of consolidated VIEs	181		270
Renewables [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount Assets [Abstract]
Restricted receivables of VIEs	17		18
Other current assets	115		89
Investments and other assets	30		29
Property, plant and equipment, cost	1,856	[2]	1,662	[2]
Accumulated depreciation and amortization	(214)		(170)
Other deferred debits	33		34
Total assets	1,837		1,662
Variable Interest Entity Consolidated Carrying Amount Liabilities [Abstract]
Accounts payable	3		2
Taxes accrued	4		10
Current maturities of long-term debt	64		66
Other current liabilities	17		17
Long-term Debt	863	[1]	907	[1]
Deferred income taxes	292		290
Asset retirement obligation	30		26
Other liabilities	33		17
Total liabilities	1,306		1,335
Net assets of consolidated VIEs	531		327
Other VIEs [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount Assets [Abstract]
Restricted receivables of VIEs	19		17
Other current assets	12		12
Investments and other assets	39		51
Property, plant and equipment, cost	18	[2]	18	[2]
Accumulated depreciation and amortization	(5)		(5)
Other deferred debits
Total assets	83		93
Variable Interest Entity Consolidated Carrying Amount Liabilities [Abstract]
Current maturities of long-term debt	16		14
Other current liabilities	11		10
Long-term Debt	26	[1]	34	[1]
Other liabilities	9		13
Total liabilities	62		71
Net assets of consolidated VIEs	21		22
Total Consolidated VIE [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount Assets [Abstract]
Restricted receivables of VIEs	2,120		1,719
Other current assets	127		101
Investments and other assets	69		80
Property, plant and equipment, cost	1,874	[2]	1,680	[2]
Accumulated depreciation and amortization	(219)		(175)
Other deferred debits	35		36
Total assets	4,006		3,441
Variable Interest Entity Consolidated Carrying Amount Liabilities [Abstract]
Accounts payable	3		2
Taxes accrued	4		10
Current maturities of long-term debt	80		80
Other current liabilities	28		27
Long-term Debt	2,139	[1]	1,966	[1]
Deferred income taxes	292		290
Asset retirement obligation	30		26
Other liabilities	42		31
Total liabilities	2,618		2,432
Net assets of consolidated VIEs	$ 1,388		$ 1,009

[1] Non-recourse to the general assets of the applicable registrant.

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