Variable Interest Entities (Consolidated VIEs) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Cash and Cash Equivalents, at Carrying Value	$ 392	$ 383	$ 463	$ 476
Restricted receivables of VIEs	1,893	1,748
Regulatory Assets, Current	1,023	877
Other current assets	458	307
Regulatory Assets, noncurrent	12,878	11,373
Investments and other assets	2,752	2,830
Total property, plant and equipment	121,397	109,967
Accumulated depreciation and amortization	(39,406)	(36,736)
Other deferred debits	17	43
Accounts payable	2,994	2,350
Current maturities of long-term debt	2,319	2,026
Other current liabilities	2,044	2,011
Long-Term debt	45,576	36,842
Deferred income taxes	14,155	12,548
Asset retirement obligations	10,200	10,249
Other Liabilities	1,753	1,631
Duke Energy Carolinas [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Cash and Cash Equivalents, at Carrying Value	14	13	13	23
Restricted receivables of VIEs	645	596
Regulatory Assets, Current	238	305
Other current assets	37	128
Regulatory Assets, noncurrent	3,159	2,766
Investments and other assets	940	999
Total property, plant and equipment	41,127	39,398
Accumulated depreciation and amortization	(14,365)	(13,521)
Other deferred debits	3	4
Accounts payable	833	753
Current maturities of long-term debt	116	356
Other current liabilities	468	519
Long-Term debt	9,187	7,711
Deferred income taxes	6,544	6,146
Asset retirement obligations	3,673	3,918
Other Liabilities	607	621
Duke Energy Progress [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Cash and Cash Equivalents, at Carrying Value	11	15	9	21
Restricted receivables of VIEs	404	349
Regulatory Assets, Current	188	264
Other current assets	57	121
Regulatory Assets, noncurrent	3,243	2,710
Investments and other assets	523	486
Total property, plant and equipment	28,419	27,313
Accumulated depreciation and amortization	(10,561)	(10,141)
Other deferred debits	2	3
Accounts payable	589	399
Current maturities of long-term debt	452	2
Other current liabilities	365	412
Long-Term debt	6,409	6,366
Deferred income taxes	3,323	3,027
Asset retirement obligations	4,508	4,567
Other Liabilities	51	45
Duke Energy Florida [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Cash and Cash Equivalents, at Carrying Value	16	8	$ 8	$ 16
Restricted receivables of VIEs	288	308
Regulatory Assets, Current	213	98
Other current assets	125	21
Regulatory Assets, noncurrent	2,480	2,725
Investments and other assets	276	292
Total property, plant and equipment	16,434	15,343
Accumulated depreciation and amortization	(4,644)	(4,720)
Other deferred debits	2	2
Accounts payable	413	322
Current maturities of long-term debt	326	13
Other current liabilities	352	452
Long-Term debt	5,799	4,253
Deferred income taxes	2,694	2,460
Asset retirement obligations	778	802
Other Liabilities	105	146
DEFPF [Member] | Duke Energy Florida [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Restricted receivables of VIEs	6
Regulatory Assets, Current	50
Other current assets	53
Regulatory Assets, noncurrent	1,142
Current maturities of long-term debt	62
Other current liabilities	17
Long-Term debt	1,217
Renewables [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity Consolidated Carrying Amount, Assets and Liabilities, Net [Abstract]
Other current assets	223	138
Total property, plant and equipment	3,419	2,015
Accumulated depreciation and amortization	(453)	(321)
Current maturities of long-term debt	198	108
Long-Term debt	1,097	968
Deferred income taxes	275	289
Other Liabilities	$ 252	$ 33