Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	2 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Oct. 31, 2016	Dec. 31, 2015	Oct. 31, 2015
Operating Revenues [Abstract]
Regulated electric		$ 21,177	$ 21,221		$ 21,379
Regulated natural gas		1,734	863		536
Nonregulated electric and other		654	659		456
Total operating revenues		23,565	22,743		22,371
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power		6,350	6,625		7,355
Cost of natural gas		632	265		141
Operation, maintenance and other		5,788	6,085		5,539
Depreciation and amortization		3,527	3,294		3,053
Property and other taxes		1,233	1,142		1,129
Impairment charges		282	18		106
Total operating expenses		17,812	17,429		17,323
Gains on Sales of Other Assets and Other, net		28	27		30
Operating Income		5,781	5,341		5,078
Other Income and Expenses [Abstract]
Equity in earnings (losses) of unconsolidated affiliates		119	(15)		69
Other income and expenses, net		352	324		290
Total other income and expenses		471	309		359
Interest Expense		1,986	1,916		1,527
Income From Continuing Operations Before Income Taxes		4,266	3,734		3,910
Income Tax Expense from Continuing Operations		1,196	1,156		1,256
Income From Continuing Operations		3,070	2,578		2,654
(Loss) Income from Discontinued Operations, net of tax		(6)	(408)		177
Net Income		3,064	2,170		2,831
Less: Net Income Attributable to Noncontrolling Interests		5	18		15
Net Income Attributable to Parent		3,059	2,152		2,816
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Pension and OPEB adjustments		3	(11)		(13)
Net unrealized gain on cash flow hedges		2	17
Reclassification into earnings from cash flow hedges		8	13		9
Unrealized gains on available for sale securities		13	2		(6)
Other comprehensive income (loss), net of tax		26	715		(274)
Comprehensive Income		3,090	2,885		2,557
Less: Comprehensive Income Attributable to Noncontrolling Interests		5	20		4
Comprehensive Income Attributable to Parent		$ 3,085	$ 2,865		$ 2,553
Income from continuing operations attributable to parent common shareholders [Abstract]
Basic		$ 4.37	$ 3.71		$ 3.80
Diluted		4.37	3.71		3.80
(Loss) Income from discontinued operations attributable to Duke Energy Corporation common shareholders [Abstract]
Basic		(0.01)	(0.60)		0.25
Diluted		(0.01)	(0.60)		0.25
Net income attributable to Duke Energy Corporation common shareholders [Abstract]
Basic		4.36	3.11		4.05
Diluted		$ 4.36	$ 3.11		$ 4.05
Weighted average shares outstanding [Abstract]
Basic		700	691		694
Diluted		700	691		694
Duke Energy Carolinas [Member]
Operating Revenues [Abstract]
Total operating revenues		$ 7,302	$ 7,322		$ 7,229
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power		1,822	1,797		1,881
Operation, maintenance and other		1,961	2,106		2,066
Depreciation and amortization		1,090	1,075		1,051
Property and other taxes		281	276		269
Impairment charges			1		1
Total operating expenses		5,154	5,255		5,268
Gains on Sales of Other Assets and Other, net		1	(5)		(1)
Operating Income		2,149	2,062		1,960
Other Income and Expenses [Abstract]
Other income and expenses, net		139	162		160
Total other income and expenses		139	162		160
Interest Expense		422	424		412
Income From Continuing Operations Before Income Taxes		1,866	1,800		1,708
Income Tax Expense from Continuing Operations		652	634		627
Net Income Attributable to Parent		1,214	1,166		1,081
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Reclassification into earnings from cash flow hedges		2	2		1
Unrealized gains on available for sale securities					1
Other comprehensive income (loss), net of tax		2	2		2
Comprehensive Income Attributable to Parent		1,216	1,168		1,083
Progress Energy [Member]
Operating Revenues [Abstract]
Total operating revenues		9,783	9,853		10,277
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power		3,417	3,644		4,224
Operation, maintenance and other		2,220	2,386		2,298
Depreciation and amortization		1,285	1,213		1,116
Property and other taxes		503	487		492
Impairment charges		156	7		12
Total operating expenses		7,581	7,737		8,142
Gains on Sales of Other Assets and Other, net		26	25		25
Operating Income		2,228	2,141		2,160
Other Income and Expenses [Abstract]
Other income and expenses, net		128	114		97
Total other income and expenses		128	114		97
Interest Expense		824	689		670
Income From Continuing Operations Before Income Taxes		1,532	1,566		1,587
Income Tax Expense from Continuing Operations		264	527		522
Income From Continuing Operations		1,268	1,039		1,065
(Loss) Income from Discontinued Operations, net of tax			2		(3)
Net Income		1,268	1,041		1,062
Less: Net Income Attributable to Noncontrolling Interests		10	10		11
Net Income Attributable to Parent		1,258	1,031		1,051
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Pension and OPEB adjustments		4	1		(10)
Net unrealized gain on cash flow hedges		5
Reclassification into earnings from cash flow hedges			8		4
Unrealized gains on available for sale securities		4	1		(1)
Other comprehensive income (loss), net of tax		13	10		(7)
Comprehensive Income		1,281	1,051		1,055
Less: Comprehensive Income Attributable to Noncontrolling Interests		10	10		11
Comprehensive Income Attributable to Parent		1,271	1,041		1,044
Duke Energy Progress [Member]
Operating Revenues [Abstract]
Total operating revenues		5,129	5,277		5,290
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power		1,609	1,830		2,029
Operation, maintenance and other		1,389	1,504		1,452
Depreciation and amortization		725	703		643
Property and other taxes		156	156		140
Impairment charges		19	1		5
Total operating expenses		3,898	4,194		4,269
Gains on Sales of Other Assets and Other, net		4	3		3
Operating Income		1,235	1,086		1,024
Other Income and Expenses [Abstract]
Other income and expenses, net		65	71		71
Total other income and expenses		65	71		71
Interest Expense		293	257		235
Income From Continuing Operations Before Income Taxes		1,007	900		860
Income Tax Expense from Continuing Operations		292	301		294
Net Income Attributable to Parent		715	599		566
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Comprehensive Income Attributable to Parent		715	599		566
Duke Energy Florida [Member]
Operating Revenues [Abstract]
Total operating revenues		4,646	4,568		4,977
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power		1,808	1,814		2,195
Operation, maintenance and other		818	865		835
Depreciation and amortization		560	509		473
Property and other taxes		347	333		352
Impairment charges		138	6		7
Total operating expenses		3,671	3,527		3,862
Gains on Sales of Other Assets and Other, net		1
Operating Income		976	1,041		1,115
Other Income and Expenses [Abstract]
Other income and expenses, net		61	44		24
Total other income and expenses		61	44		24
Interest Expense		279	212		198
Income From Continuing Operations Before Income Taxes		758	873		941
Income Tax Expense from Continuing Operations		46	322		342
Net Income Attributable to Parent		712	551		599
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Unrealized gains on available for sale securities		3	1
Other comprehensive income (loss), net of tax		3	1
Comprehensive Income Attributable to Parent		715	552		599
Duke Energy Ohio [Member]
Operating Revenues [Abstract]
Regulated electric		1,373	1,410		1,331
Regulated natural gas		508	503		541
Nonregulated electric and other		42	31		33
Total operating revenues		1,923	1,944		1,905
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power		369	442		446
Fuel used in electric generation and purchased power - nonregulated		58	51		47
Cost of natural gas		107	103		141
Operation, maintenance and other		524	512		495
Depreciation and amortization		261	233		227
Property and other taxes		278	258		254
Impairment charges		1
Total operating expenses		1,598	1,599		1,610
Gains on Sales of Other Assets and Other, net		1	2		8
Operating Income		326	347		303
Other Income and Expenses [Abstract]
Other income and expenses, net		17	9		6
Total other income and expenses		17	9		6
Interest Expense		91	86		79
Income From Continuing Operations Before Income Taxes		252	270		230
Income Tax Expense from Continuing Operations		59	78		81
Income From Continuing Operations		193	192		149
(Loss) Income from Discontinued Operations, net of tax		(1)	36		23
Net Income Attributable to Parent		192	228		172
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Comprehensive Income Attributable to Parent		192	228		172
Duke Energy Indiana [Member]
Operating Revenues [Abstract]
Total operating revenues		3,047	2,958		2,890
Operating Expenses [Abstract]
Fuel used in electric generation and purchased power		966	909		982
Operation, maintenance and other		733	723		682
Depreciation and amortization		458	496		434
Property and other taxes		76	58		61
Impairment charges		18	8		88
Total operating expenses		2,251	2,194		2,247
Gains on Sales of Other Assets and Other, net			1		1
Operating Income		796	765		644
Other Income and Expenses [Abstract]
Other income and expenses, net		37	22		11
Total other income and expenses		37	22		11
Interest Expense		178	181		176
Income From Continuing Operations Before Income Taxes		655	606		479
Income Tax Expense from Continuing Operations		301	225		163
Net Income Attributable to Parent		354	381		316
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Reclassification into earnings from cash flow hedges			(1)		(2)
Other comprehensive income (loss), net of tax			(1)		(2)
Comprehensive Income Attributable to Parent		354	$ 380		$ 314
Piedmont Natural Gas [Member]
Operating Revenues [Abstract]
Regulated natural gas	$ 320	1,319		$ 1,139		$ 1,372
Nonregulated electric and other	2	9		10		11
Total operating revenues	322	1,328		1,149		1,383
Operating Expenses [Abstract]
Cost of natural gas	144	524		391		644
Operation, maintenance and other	52	315		353		305
Depreciation and amortization	23	148		137		129
Property and other taxes	7	48		43		42
Impairment charges		7
Total operating expenses	226	1,042		924		1,120
Operating Income	96	286		225		263
Other Income and Expenses [Abstract]
Equity in earnings (losses) of unconsolidated affiliates	2	(6)		29		34
Gain on sale of unconsolidated affiliates				133
Other income and expenses, net				(1)		(1)
Total other income and expenses	2	(6)		161		33
Interest Expense	12	79		69		69
Income From Continuing Operations Before Income Taxes	86	201		317		227
Income Tax Expense from Continuing Operations	32	62		124		90
Net Income Attributable to Parent	54	139		193		137
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Net unrealized gain on cash flow hedges				(3)		(2)
Reclassification into earnings from cash flow hedges				4		1
Other comprehensive income (loss), net of tax				1		(1)
Comprehensive Income Attributable to Parent	$ 54	$ 139		$ 194		$ 136