Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Current Assets
Cash and cash equivalents	$ 304	$ 358
Receivables (net of allowance for doubtful accounts)	612	779
Receivables of VIEs (net of allowance for doubtful accounts)	2,205	1,995
Inventory	3,177	3,250
Regulatory assets	1,741	1,437
Other	437	634
Total current assets	8,476	8,453
Property, Plant and Equipment
Cost	130,616	127,507
Accumulated depreciation and amortization	(42,499)	(41,537)
Generation facilities to be retired, net	378	421
Net property, plant and equipment	88,495	86,391
Other Noncurrent Assets
Goodwill	19,396	19,396
Regulatory assets	12,505	12,442
Nuclear decommissioning trust funds	7,132	7,097
Investments in equity method unconsolidated affiliates	1,168	1,175
Other	3,087	2,960
Total other noncurrent assets	43,288	43,070
Total Assets	140,259	137,914
Current Liabilities
Accounts payable	2,686	3,043
Notes payable and commercial paper	3,329	2,163
Taxes accrued	494	551
Interest accrued	530	525
Current maturities of long-term debt	2,852	3,244
Asset retirement obligations	716	689
Regulatory liabilities	485	402
Other	1,699	1,865
Total current liabilities	12,791	12,482
Long-Term Debt	49,863	49,035
Other Noncurrent Liabilities
Deferred income taxes	6,977	6,621
Asset retirement obligations	9,753	9,486
Regulatory liabilities	15,355	15,330
Accrued pension and other post-retirement benefit costs	1,014	1,103
Investment tax credits	534	539
Other	1,457	1,581
Total other noncurrent liabilities	35,090	34,660
Equity
Common stock	1	1
Additional paid-in capital	39,682	38,792
Retained earnings	2,894	3,013
Accumulated other comprehensive loss	(70)	(67)
Total Parent stockholders' equity	42,507	41,739
Noncontrolling interests	8	(2)
Total equity	42,515	41,737
Total Liabilities and Equity	140,259	137,914
Duke Energy Carolinas [Member]
Current Assets
Cash and cash equivalents	16	16
Receivables (net of allowance for doubtful accounts)	172	200
Receivables of VIEs (net of allowance for doubtful accounts)	704	640
Receivables from affiliated companies	117	95
Inventory	984	971
Regulatory assets	420	299
Other	21	19
Total current assets	2,434	2,240
Property, Plant and Equipment
Cost	43,429	42,939
Accumulated depreciation and amortization	(15,248)	(15,063)
Net property, plant and equipment	28,181	27,876
Other Noncurrent Assets
Regulatory assets	3,234	2,853
Nuclear decommissioning trust funds	3,790	3,772
Other	1,036	979
Total other noncurrent assets	8,060	7,604
Total Assets	38,675	37,720
Current Liabilities
Accounts payable	809	842
Accounts payable to affiliated companies	158	209
Notes payable to affiliated companies	740	104
Taxes accrued	158	234
Interest accrued	109	108
Current maturities of long-term debt	505	1,205
Asset retirement obligations	227	337
Regulatory liabilities	131	126
Other	412	486
Total current liabilities	3,249	3,651
Long-Term Debt	9,589	8,598
Long-Term Debt Payable to Affiliated Companies	300	300
Other Noncurrent Liabilities
Deferred income taxes	3,507	3,413
Asset retirement obligations	3,592	3,273
Regulatory liabilities	6,292	6,231
Accrued pension and other post-retirement benefit costs	99	95
Investment tax credits	230	232
Other	515	566
Total other noncurrent liabilities	14,235	13,810
Commitments and Contingencies
Equity
Member's equity	11,308	11,368
Accumulated other comprehensive loss	(6)	(7)
Total member's equity	11,302	11,361
Total Liabilities and Equity	38,675	37,720
Progress Energy [Member]
Current Assets
Cash and cash equivalents	37	40
Receivables (net of allowance for doubtful accounts)	130	123
Receivables of VIEs (net of allowance for doubtful accounts)	969	780
Receivables from affiliated companies	3	31
Notes receivable from affiliated companies	309	240
Inventory	1,521	1,592
Regulatory assets	970	741
Other	356	334
Total current assets	4,295	3,881
Property, Plant and Equipment
Cost	48,896	47,323
Accumulated depreciation and amortization	(16,380)	(15,857)
Generation facilities to be retired, net	378	421
Net property, plant and equipment	32,894	31,887
Other Noncurrent Assets
Goodwill	3,655	3,655
Regulatory assets	5,736	6,010
Nuclear decommissioning trust funds	3,342	3,324
Other	992	931
Total other noncurrent assets	13,725	13,920
Total Assets	50,914	49,688
Current Liabilities
Accounts payable	816	1,006
Accounts payable to affiliated companies	232	251
Notes payable to affiliated companies	1,152	805
Taxes accrued	181	101
Interest accrued	211	212
Current maturities of long-term debt	1,321	771
Asset retirement obligations	386	295
Regulatory liabilities	233	213
Other	711	729
Total current liabilities	5,243	4,383
Long-Term Debt	16,723	16,916
Long-Term Debt Payable to Affiliated Companies	150	150
Other Noncurrent Liabilities
Deferred income taxes	3,806	3,502
Asset retirement obligations	5,052	5,119
Regulatory liabilities	5,193	5,306
Accrued pension and other post-retirement benefit costs	519	545
Other	256	302
Total other noncurrent liabilities	14,826	14,774
Commitments and Contingencies
Equity
Additional paid-in capital	9,143	9,143
Retained earnings	4,855	4,350
Accumulated other comprehensive loss	(26)	(25)
Total Parent stockholders' equity	13,972	13,468
Noncontrolling interests		(3)
Total equity	13,972	13,465
Total Liabilities and Equity	50,914	49,688
Duke Energy Progress [Member]
Current Assets
Cash and cash equivalents	18	20
Receivables (net of allowance for doubtful accounts)	50	56
Receivables of VIEs (net of allowance for doubtful accounts)	568	459
Receivables from affiliated companies	1	3
Inventory	976	1,017
Regulatory assets	532	352
Other	33	97
Total current assets	2,178	2,004
Property, Plant and Equipment
Cost	30,535	29,583
Accumulated depreciation and amortization	(11,296)	(10,903)
Generation facilities to be retired, net	378	421
Net property, plant and equipment	19,617	19,101
Other Noncurrent Assets
Regulatory assets	3,573	3,507
Nuclear decommissioning trust funds	2,627	2,588
Other	635	599
Total other noncurrent assets	6,835	6,694
Total Assets	28,630	27,799
Current Liabilities
Accounts payable	375	402
Accounts payable to affiliated companies	175	179
Notes payable to affiliated companies	540	240
Taxes accrued	90	64
Interest accrued	103	102
Current maturities of long-term debt	603	3
Asset retirement obligations	381	295
Regulatory liabilities	157	139
Other	344	376
Total current liabilities	2,768	1,800
Long-Term Debt	6,605	7,204
Long-Term Debt Payable to Affiliated Companies	150	150
Other Noncurrent Liabilities
Deferred income taxes	1,957	1,883
Asset retirement obligations	4,454	4,378
Regulatory liabilities	3,998	3,999
Accrued pension and other post-retirement benefit costs	243	248
Investment tax credits	142	143
Other	48	45
Total other noncurrent liabilities	10,842	10,696
Commitments and Contingencies
Equity
Total member's equity	8,265	7,949
Total Liabilities and Equity	28,630	27,799
Duke Energy Florida [Member]
Current Assets
Cash and cash equivalents	14	13
Receivables (net of allowance for doubtful accounts)	78	65
Receivables of VIEs (net of allowance for doubtful accounts)	400	321
Receivables from affiliated companies	6	2
Notes receivable from affiliated companies	423	313
Inventory	546	574
Regulatory assets	439	389
Other	183	86
Total current assets	2,089	1,763
Property, Plant and Equipment
Cost	18,353	17,730
Accumulated depreciation and amortization	(5,079)	(4,947)
Net property, plant and equipment	13,274	12,783
Other Noncurrent Assets
Regulatory assets	2,163	2,503
Nuclear decommissioning trust funds	715	736
Other	307	284
Total other noncurrent assets	3,185	3,523
Total Assets	18,548	18,069
Current Liabilities
Accounts payable	440	602
Accounts payable to affiliated companies	63	74
Taxes accrued	115	34
Interest accrued	53	56
Current maturities of long-term debt	269	768
Asset retirement obligations	5	0
Regulatory liabilities	76	74
Other	357	334
Total current liabilities	1,378	1,942
Long-Term Debt	7,183	6,327
Other Noncurrent Liabilities
Deferred income taxes	2,007	1,761
Asset retirement obligations	597	742
Regulatory liabilities	1,194	1,307
Accrued pension and other post-retirement benefit costs	243	264
Other	58	108
Total other noncurrent liabilities	4,099	4,182
Commitments and Contingencies
Equity
Member's equity	5,890	5,614
Accumulated other comprehensive loss	(2)	4
Total member's equity	5,888	5,618
Total Liabilities and Equity	18,548	18,069
Duke Energy Ohio [Member]
Current Assets
Cash and cash equivalents	7	12
Receivables (net of allowance for doubtful accounts)	87	68
Receivables from affiliated companies	71	133
Notes receivable from affiliated companies		14
Inventory	124	133
Regulatory assets	46	49
Other	30	39
Total current assets	365	448
Property, Plant and Equipment
Cost	9,024	8,732
Accumulated depreciation and amortization	(2,696)	(2,691)
Net property, plant and equipment	6,328	6,041
Other Noncurrent Assets
Goodwill	920	920
Regulatory assets	425	445
Other	63	21
Total other noncurrent assets	1,408	1,386
Total Assets	8,101	7,875
Current Liabilities
Accounts payable	267	313
Accounts payable to affiliated companies	47	62
Notes payable to affiliated companies	219	29
Taxes accrued	127	190
Interest accrued	21	21
Current maturities of long-term debt	452	3
Asset retirement obligations	5	3
Regulatory liabilities	51	36
Other	71	71
Total current liabilities	1,260	728
Long-Term Debt	1,589	2,039
Long-Term Debt Payable to Affiliated Companies	25	25
Other Noncurrent Liabilities
Deferred income taxes	778	781
Asset retirement obligations	84	81
Regulatory liabilities	896	891
Accrued pension and other post-retirement benefit costs	83	59
Other	96	108
Total other noncurrent liabilities	1,937	1,920
Equity
Common stock	762	762
Additional paid-in capital	2,776	2,670
Retained earnings	(248)	(269)
Total Parent stockholders' equity	3,290	3,163
Total Liabilities and Equity	8,101	7,875
Duke Energy Indiana [Member]
Current Assets
Cash and cash equivalents	24	9
Receivables (net of allowance for doubtful accounts)	54	57
Receivables from affiliated companies	89	125
Inventory	470	450
Regulatory assets	191	165
Other	52	30
Total current assets	880	836
Property, Plant and Equipment
Cost	15,213	14,948
Accumulated depreciation and amortization	(4,767)	(4,662)
Net property, plant and equipment	10,446	10,286
Other Noncurrent Assets
Regulatory assets	1,021	978
Other	224	189
Total other noncurrent assets	1,245	1,167
Total Assets	12,571	12,289
Current Liabilities
Accounts payable	171	196
Accounts payable to affiliated companies	58	78
Notes payable to affiliated companies	221	161
Taxes accrued	54	95
Interest accrued	59	57
Current maturities of long-term debt	62	3
Asset retirement obligations	98	54
Regulatory liabilities	19	24
Other	123	104
Total current liabilities	865	772
Long-Term Debt	3,570	3,630
Long-Term Debt Payable to Affiliated Companies	150	150
Other Noncurrent Liabilities
Deferred income taxes	957	925
Asset retirement obligations	758	727
Regulatory liabilities	1,755	1,723
Accrued pension and other post-retirement benefit costs	111	76
Investment tax credits	147	147
Other	14	18
Total other noncurrent liabilities	3,742	3,616
Equity
Total member's equity	4,244	4,121
Total Liabilities and Equity	12,571	12,289
Piedmont Natural Gas [Member]
Current Assets
Cash and cash equivalents	8	19
Receivables (net of allowance for doubtful accounts)	109	275
Receivables from affiliated companies	11	7
Notes receivable from affiliated companies	77
Inventory	38	66
Regulatory assets	35	95
Other	36	52
Total current assets	314	514
Property, Plant and Equipment
Cost	7,089	6,725
Accumulated depreciation and amortization	(1,533)	(1,479)
Net property, plant and equipment	5,556	5,246
Other Noncurrent Assets
Goodwill	49	49
Regulatory assets	297	283
Investments in equity method unconsolidated affiliates	62	61
Other	65	65
Total other noncurrent assets	473	458
Total Assets	6,343	6,218
Current Liabilities
Accounts payable	133	125
Accounts payable to affiliated companies	1	13
Notes payable to affiliated companies		364
Taxes accrued	23	19
Interest accrued	31	31
Current maturities of long-term debt	250	250
Regulatory liabilities	51	3
Other	53	69
Total current liabilities	542	874
Long-Term Debt	1,787	1,787
Other Noncurrent Liabilities
Deferred income taxes	569	564
Asset retirement obligations	15	15
Regulatory liabilities	1,183	1,141
Accrued pension and other post-retirement benefit costs	3	5
Other	180	170
Total other noncurrent liabilities	1,950	1,895
Commitments and Contingencies
Equity
Common stock	1,160	860
Retained earnings	904	802
Total Parent stockholders' equity	2,064	1,662
Total Liabilities and Equity	$ 6,343	$ 6,218