Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Current Assets [Abstract]
Cash and cash equivalents	$ 857	$ 2,036
Receivables (net of allowance for doubtful accounts)	703	791
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	1,748	1,973
Inventory	3,810	3,459
Assets held for sale		364
Regulatory assets	877	1,115
Other	327	1,837
Total current assets	8,322	11,575
Investments and Other Assets [Abstract]
Investments in equity method unconsolidated affiliates	499	358
Nuclear decommissioning trust funds	5,825	5,546
Goodwill	16,343	16,321
Assets held for sale		2,642
Other	3,042	3,008
Total investments and other assets	25,709	27,875
Property, Plant and Equipment [Abstract]
Cost	112,826	104,861
Accumulated depreciation and amortization	(37,665)	(34,824)
Generation facilities to be retired, net	548	9
Net property, plant and equipment	75,709	70,046
Regulatory Assets and Deferred Debits [Abstract]
Regulatory assets	11,373	11,042
Other	43	19
Total regulatory assets and deferred debits	11,416	11,061
Total Assets	121,156	120,557
Current Liabilities [Abstract]
Accounts payable	2,400	2,271
Notes payable and commercial paper	3,633	2,514
Taxes accrued	348	569
Interest accrued	430	418
Current maturities of long-term debt	2,074	2,807
Liabilities associated with assets held for sale		262
Regulatory liabilities	400	204
Other	2,115	2,188
Total current liabilities	11,400	11,233
Long-Term debt	37,495	37,061
Deferred Credits and Other Liabilities [Abstract]
Deferred income taxes	12,705	13,423
Investment tax credits	472	427
Accrued pension and other post-retirement benefit costs	1,088	1,145
Liabilities associated with assets held for sale		35
Asset retirement obligations	10,264	8,466
Regulatory liabilities	6,255	6,193
Other	1,706	1,675
Total deferred credits and other liabilities	$ 32,490	$ 31,364
Commitments and Contingencies
Equity [Abstract]
Common stock	$ 1	$ 1
Additional paid-in capital	37,968	39,405
Retained earnings	2,564	2,012
Accumulated other comprehensive (loss) income	(806)	(543)
Total Common Shareholders' Equity	39,727	40,875
Noncontrolling interests	44	24
Total equity	39,771	40,899
Total Liabilities and Equity	121,156	120,557
Duke Energy Carolinas [Member]
Current Assets [Abstract]
Cash and cash equivalents	13	13
Receivables (net of allowance for doubtful accounts)	142	129
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	596	647
Receivables from affiliated companies	107	75
Notes receivable from affiliated companies	163	150
Inventory	1,276	1,124
Regulatory assets	305	399
Other	128	77
Total current assets	2,730	2,614
Investments and Other Assets [Abstract]
Nuclear decommissioning trust funds	3,050	3,042
Other	999	959
Total investments and other assets	4,049	4,001
Property, Plant and Equipment [Abstract]
Cost	39,398	37,372
Accumulated depreciation and amortization	(13,521)	(12,700)
Net property, plant and equipment	25,877	24,672
Regulatory Assets and Deferred Debits [Abstract]
Regulatory assets	2,766	2,465
Other	4	4
Total regulatory assets and deferred debits	2,770	2,469
Total Assets	35,426	33,756
Current Liabilities [Abstract]
Accounts payable	753	709
Accounts payable to affiliated companies	229	154
Taxes accrued	25	146
Interest accrued	95	95
Current maturities of long-term debt	356	507
Regulatory liabilities	39	34
Other	519	434
Total current liabilities	2,016	2,079
Long-Term debt	7,711	7,546
Long-term debt payable to affiliated companies	300	300
Deferred Credits and Other Liabilities [Abstract]
Deferred income taxes	6,146	5,812
Investment tax credits	199	204
Accrued pension and other post-retirement benefit costs	107	111
Asset retirement obligations	3,918	3,428
Regulatory liabilities	2,802	2,710
Other	621	642
Total deferred credits and other liabilities	$ 13,793	$ 12,907
Commitments and Contingencies
Equity [Abstract]
Member's equity	$ 11,617	$ 10,937
Accumulated other comprehensive (loss) income	(11)	(13)
Total Member's Equity	11,606	10,924
Total Liabilities and Equity	35,426	33,756
Progress Energy [Member]
Current Assets [Abstract]
Cash and cash equivalents	44	42
Receivables (net of allowance for doubtful accounts)	151	129
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	658	741
Receivables from affiliated companies	375	59
Notes receivable from affiliated companies		220
Inventory	1,751	1,590
Regulatory assets	362	491
Other	156	1,285
Total current assets	3,497	4,557
Investments and Other Assets [Abstract]
Nuclear decommissioning trust funds	2,775	2,503
Goodwill	3,655	3,655
Other	834	670
Total investments and other assets	7,264	6,828
Property, Plant and Equipment [Abstract]
Cost	42,666	38,650
Accumulated depreciation and amortization	(14,867)	(13,506)
Generation facilities to be retired, net	548
Net property, plant and equipment	28,347	25,144
Regulatory Assets and Deferred Debits [Abstract]
Regulatory assets	5,435	5,408
Other	5	5
Total regulatory assets and deferred debits	5,440	5,413
Total Assets	44,548	41,942
Current Liabilities [Abstract]
Accounts payable	722	847
Accounts payable to affiliated companies	311	203
Notes payable to affiliated companies	1,308	835
Taxes accrued	53	114
Interest accrued	195	184
Current maturities of long-term debt	315	1,507
Regulatory liabilities	286	106
Other	891	1,021
Total current liabilities	4,081	4,817
Long-Term debt	13,999	13,161
Long-term debt payable to affiliated companies	150
Deferred Credits and Other Liabilities [Abstract]
Deferred income taxes	4,790	4,759
Accrued pension and other post-retirement benefit costs	536	533
Asset retirement obligations	5,369	4,711
Regulatory liabilities	2,387	2,379
Other	383	406
Total deferred credits and other liabilities	$ 13,465	$ 12,788
Commitments and Contingencies
Equity [Abstract]
Additional paid-in capital	$ 8,092	$ 7,467
Retained earnings	4,831	3,782
Accumulated other comprehensive (loss) income	(48)	(41)
Total Common Shareholders' Equity	12,875	11,208
Noncontrolling interests	(22)	(32)
Total equity	12,853	11,176
Total Liabilities and Equity	44,548	41,942
Duke Energy Progress [Member]
Current Assets [Abstract]
Cash and cash equivalents	15	9
Receivables (net of allowance for doubtful accounts)	87	43
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	349	436
Receivables from affiliated companies	16	10
Notes receivable from affiliated companies		237
Inventory	1,088	966
Regulatory assets	264	287
Other	121	384
Total current assets	1,940	2,372
Investments and Other Assets [Abstract]
Nuclear decommissioning trust funds	2,035	1,701
Other	486	412
Total investments and other assets	2,521	2,113
Property, Plant and Equipment [Abstract]
Cost	27,313	24,207
Accumulated depreciation and amortization	(10,141)	(9,021)
Generation facilities to be retired, net	548
Net property, plant and equipment	17,720	15,186
Regulatory Assets and Deferred Debits [Abstract]
Regulatory assets	2,710	2,675
Other	3	3
Total regulatory assets and deferred debits	2,713	2,678
Total Assets	24,894	22,349
Current Liabilities [Abstract]
Accounts payable	399	481
Accounts payable to affiliated companies	190	120
Notes payable to affiliated companies	209
Taxes accrued	15	47
Interest accrued	96	81
Current maturities of long-term debt	2	945
Regulatory liabilities	85	71
Other	412	409
Total current liabilities	1,408	2,154
Long-Term debt	6,366	5,225
Long-term debt payable to affiliated companies	150
Deferred Credits and Other Liabilities [Abstract]
Deferred income taxes	3,027	2,908
Investment tax credits	132	79
Accrued pension and other post-retirement benefit costs	262	290
Asset retirement obligations	4,567	3,905
Regulatory liabilities	1,878	1,832
Other	45	89
Total deferred credits and other liabilities	9,911	9,103
Equity [Abstract]
Common stock		2,159
Member's equity	7,059
Retained earnings		3,708
Total equity	7,059	5,867
Total Member's Equity	7,059
Total Liabilities and Equity	24,894	22,349
Duke Energy Florida [Member]
Current Assets [Abstract]
Cash and cash equivalents	8	8
Receivables (net of allowance for doubtful accounts)	60	84
Restricted receivables of variable interest entities (net of allowance for doubtful accounts)	308	305
Receivables from affiliated companies	84	40
Notes receivable from affiliated companies	0	0
Inventory	663	623
Regulatory assets	98	203
Other	21	521
Total current assets	1,242	1,784
Investments and Other Assets [Abstract]
Nuclear decommissioning trust funds	740	803
Other	292	204
Total investments and other assets	1,032	1,007
Property, Plant and Equipment [Abstract]
Cost	15,343	14,433
Accumulated depreciation and amortization	(4,720)	(4,478)
Net property, plant and equipment	10,623	9,955
Regulatory Assets and Deferred Debits [Abstract]
Regulatory assets	2,725	2,733
Other	2	2
Total regulatory assets and deferred debits	2,727	2,735
Total Assets	15,624	15,481
Current Liabilities [Abstract]
Accounts payable	322	365
Accounts payable to affiliated companies	116	70
Notes payable to affiliated companies	813	84
Taxes accrued	132	65
Interest accrued	43	47
Current maturities of long-term debt	13	562
Regulatory liabilities	200	35
Other	452	586
Total current liabilities	2,091	1,814
Long-Term debt	4,253	4,261
Deferred Credits and Other Liabilities [Abstract]
Deferred income taxes	2,460	2,452
Accrued pension and other post-retirement benefit costs	242	221
Asset retirement obligations	802	806
Regulatory liabilities	509	547
Other	146	158
Total deferred credits and other liabilities	$ 4,159	$ 4,184
Commitments and Contingencies
Equity [Abstract]
Common stock		$ 1,762
Member's equity	$ 5,121
Retained earnings		3,460
Total equity	5,121	5,222
Total Member's Equity	5,121
Total Liabilities and Equity	15,624	15,481
Duke Energy Ohio [Member]
Current Assets [Abstract]
Cash and cash equivalents	14	20
Receivables (net of allowance for doubtful accounts)	66	93
Receivables from affiliated companies	84	107
Notes receivable from affiliated companies		145
Inventory	105	97
Assets held for sale		316
Regulatory assets	36	49
Other	110	167
Total current assets	415	994
Investments and Other Assets [Abstract]
Goodwill	920	920
Assets held for sale		2,605
Other	20	23
Total investments and other assets	940	3,548
Property, Plant and Equipment [Abstract]
Cost	7,750	7,141
Accumulated depreciation and amortization	(2,507)	(2,213)
Generation facilities to be retired, net		9
Net property, plant and equipment	5,243	4,937
Regulatory Assets and Deferred Debits [Abstract]
Regulatory assets	497	512
Other	2	2
Total regulatory assets and deferred debits	499	514
Total Assets	7,097	9,993
Current Liabilities [Abstract]
Accounts payable	207	209
Accounts payable to affiliated companies	53	74
Notes payable to affiliated companies	103	491
Taxes accrued	171	163
Interest accrued	18	19
Current maturities of long-term debt	106	157
Liabilities associated with assets held for sale		246
Regulatory liabilities	12	10
Other	153	66
Total current liabilities	823	1,435
Long-Term debt	1,467	1,578
Long-term debt payable to affiliated companies	25	25
Deferred Credits and Other Liabilities [Abstract]
Deferred income taxes	1,407	1,765
Accrued pension and other post-retirement benefit costs	56	48
Liabilities associated with assets held for sale		34
Asset retirement obligations	125	27
Regulatory liabilities	245	241
Other	165	166
Total deferred credits and other liabilities	1,998	2,281
Equity [Abstract]
Common stock	762	762
Additional paid-in capital	2,720	4,782
Retained earnings	(698)	(870)
Total equity	2,784	4,674
Total Liabilities and Equity	7,097	9,993
Duke Energy Indiana [Member]
Current Assets [Abstract]
Cash and cash equivalents	9	6
Receivables (net of allowance for doubtful accounts)	96	87
Receivables from affiliated companies	71	115
Notes receivable from affiliated companies	83
Inventory	570	537
Regulatory assets	102	93
Other	15	326
Total current assets	946	1,164
Investments and Other Assets [Abstract]
Total investments and other assets	212	251
Property, Plant and Equipment [Abstract]
Cost	14,007	13,034
Accumulated depreciation and amortization	(4,484)	(4,219)
Net property, plant and equipment	9,523	8,815
Regulatory Assets and Deferred Debits [Abstract]
Regulatory assets	716	685
Other	2	2
Total regulatory assets and deferred debits	718	687
Total Assets	11,399	10,917
Current Liabilities [Abstract]
Accounts payable	189	179
Accounts payable to affiliated companies	83	58
Notes payable to affiliated companies		71
Taxes accrued	89	54
Interest accrued	56	56
Current maturities of long-term debt	547	5
Regulatory liabilities	62	54
Other	97	98
Total current liabilities	1,123	575
Long-Term debt	3,071	3,614
Long-term debt payable to affiliated companies	150	150
Deferred Credits and Other Liabilities [Abstract]
Deferred income taxes	1,657	1,591
Investment tax credits	138	139
Accrued pension and other post-retirement benefit costs	80	82
Asset retirement obligations	525	32
Regulatory liabilities	754	796
Other	65	90
Total deferred credits and other liabilities	$ 3,219	$ 2,730
Commitments and Contingencies
Equity [Abstract]
Common stock	$ 1	$ 1
Additional paid-in capital	1,384	1,384
Retained earnings	2,450	2,460
Accumulated other comprehensive (loss) income	1	3
Total equity	3,836	3,848
Total Liabilities and Equity	$ 11,399	$ 10,917