Condensed Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010
ASSETS
Cash and cash equivalents	$ 2,110		$ 1,670
Short-term investments	190
Receivables (net of allowance for doubtful accounts)	784		764
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	1,157		1,302
Inventory	1,588		1,318
Other	1,051		1,169
Total current assets	6,880		6,223
Investments and Other Assets
Investments in equity method unconsolidated affiliates	460		444
Nuclear decommissioning trust funds	2,060		2,014
Goodwill	3,849		3,858
Intangibles, net	363		467
Notes receivable	62		42
Restricted other assets of variable interest entities	135		139
Other	2,231		2,291
Total investments and other assets	9,160		9,255
Property, Plant and Equipment
Cost	60,537		57,597
Cost, variable interest entities	913		942
Less accumulated depreciation and amortization	18,789		18,195
Net property, plant and equipment	42,661		40,344
Regulatory Assets and Deferred Debits
Regulatory assets	3,672		3,135
Other	153		133
Total regulatory assets and deferred debits	3,825		3,268
Total Assets	62,526	[1]	59,090	[1]
LIABILITIES AND EQUITY
Accounts payable	1,433		1,387
Notes payable and commercial paper	154
Non-recourse notes payable of variable interest entities	273		216
Taxes accrued	431		412
Interest accrued	252		237
Current maturities of long-term debt	1,894		275
Other	1,091		1,370
Total current liabilities	5,528		3,897
Long-term Debt	17,730		16,959
Non-recourse Long-term Debt of Variable Interest Entities	949		976
Deferred Credits and Other Liabilities
Deferred income taxes	7,581		6,978
Investment tax credits	384		359
Accrued pension and other post-retirement benefit costs	856		944
Asset retirement obligations	1,936		1,816
Regulatory liabilities	2,919		2,876
Other	1,778		1,632
Total deferred credits and other liabilities	15,454		14,605
Commitments and Contingencies
Equity
Common Stock	1		1
Additional paid-in capital	21,132		21,023
Retained earnings (deficit)	1,873		1,496
Accumulated other comprehensive (loss) income	(234)		2
Total common stockholder's equity	22,772		22,522
Noncontrolling interests	93		131
Total equity	22,865		22,653
Total Liabilities and Equity	62,526		59,090
Duke Energy Carolinas [Member]
ASSETS
Cash and cash equivalents	289		153
Receivables (net of allowance for doubtful accounts)	1,187		634
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	581		637
Inventory	917		716
Other	278		433
Total current assets	3,252		2,573
Investments and Other Assets
Nuclear decommissioning trust funds	2,060		2,014
Other	968		1,099
Total investments and other assets	3,028		3,113
Property, Plant and Equipment
Cost	33,000		31,191
Less accumulated depreciation and amortization	11,349		11,126
Net property, plant and equipment	21,651		20,065
Regulatory Assets and Deferred Debits
Regulatory assets	1,894		1,576
Other	71		61
Total regulatory assets and deferred debits	1,965		1,637
Total Assets	29,896		27,388
LIABILITIES AND EQUITY
Accounts payable	793		705
Taxes accrued	126		114
Interest accrued	115		109
Current maturities of long-term debt	1,178		8
Other	398		636
Total current liabilities	2,610		1,572
Long-term Debt	7,796		7,462
Non-recourse Long-term Debt of Variable Interest Entities	300		300
Deferred Credits and Other Liabilities
Deferred income taxes	4,555		3,988
Investment tax credits	233		205
Accrued pension and other post-retirement benefit costs	248		242
Asset retirement obligations	1,846		1,728
Regulatory liabilities	1,928		1,940
Other	926		1,035
Total deferred credits and other liabilities	9,736		9,138
Commitments and Contingencies
Equity
Member's Equity	9,473		8,938
Accumulated other comprehensive (loss) income	(19)		(22)
Total member's equity	9,454		8,916
Total Liabilities and Member's Equity	29,896		27,388
Duke Energy Ohio [Member]
ASSETS
Cash and cash equivalents	99		228
Receivables (net of allowance for doubtful accounts)	681		868
Inventory	243		254
Other	220		141
Total current assets	1,243		1,491
Investments and Other Assets
Goodwill	921		921
Intangibles, net	143		248
Other	58		62
Total investments and other assets	1,122		1,231
Property, Plant and Equipment
Cost	10,632		10,259
Less accumulated depreciation and amortization	2,594		2,411
Net property, plant and equipment	8,038		7,848
Regulatory Assets and Deferred Debits
Regulatory assets	520		440
Other	16		14
Total regulatory assets and deferred debits	536		454
Total Assets	10,939		11,024
LIABILITIES AND EQUITY
Accounts payable	402		431
Taxes accrued	180		153
Interest accrued	23		22
Current maturities of long-term debt	507		7
Other	122		135
Total current liabilities	1,234		748
Long-term Debt	2,048		2,557
Deferred Credits and Other Liabilities
Deferred income taxes	1,853		1,640
Investment tax credits	8		9
Accrued pension and other post-retirement benefit costs	147		187
Asset retirement obligations	27		27
Regulatory liabilities	273		265
Other	182		127
Total deferred credits and other liabilities	2,490		2,255
Commitments and Contingencies
Equity
Common Stock	762		762
Additional paid-in capital	5,085		5,570
Retained earnings (deficit)	(652)		(846)
Accumulated other comprehensive (loss) income	(28)		(22)
Total common stockholder's equity	5,167		5,464
Total Liabilities and Equity	10,939		11,024
Duke Energy Indiana [Member]
ASSETS
Cash and cash equivalents	16		54
Receivables (net of allowance for doubtful accounts)	198		395
Inventory	330		267
Other	135		121
Total current assets	679		837
Investments and Other Assets
Intangibles, net	50		64
Other	113		126
Total investments and other assets	163		190
Property, Plant and Equipment
Cost	11,791		11,213
Less accumulated depreciation and amortization	3,393		3,341
Net property, plant and equipment	8,398		7,872
Regulatory Assets and Deferred Debits
Regulatory assets	798		710
Other	24		22
Total regulatory assets and deferred debits	822		732
Total Assets	10,062		9,631
LIABILITIES AND EQUITY
Accounts payable	273		303
Notes payable and commercial paper	300
Taxes accrued	74		45
Interest accrued	50		47
Current maturities of long-term debt	6		11
Other	93		110
Total current liabilities	796		516
Long-term Debt	3,453		3,461
Deferred Credits and Other Liabilities
Deferred income taxes	927		973
Investment tax credits	143		145
Accrued pension and other post-retirement benefit costs	161		212
Asset retirement obligations	43		46
Regulatory liabilities	683		651
Other	122		60
Total deferred credits and other liabilities	2,079		2,087
Commitments and Contingencies
Equity
Common Stock	1		1
Additional paid-in capital	1,358		1,358
Retained earnings (deficit)	2,368		2,200
Accumulated other comprehensive (loss) income	7		8
Total common stockholder's equity	3,734		3,567
Total Liabilities and Equity	$ 10,062		$ 9,631

[1] Includes assets held for sale and assets of entities in discontinued operations. See Note 13 for description and carrying value of investments accounted for under the equity method of accounting within each segment.