Condensed Consolidated Statements of Changes in Equity - USD ($) $ in Millions	Total		Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]		Foreign Currency Translation Adjustments [Member]	Net Gains (Losses) on Cash Flow Hedges [Member]	Net Unrealized Gains (Losses) on Available for Sale Securities [Member]	Pension and OPEB Adjustments [Member]	Common Stockholders' Equity [Member]		Noncontrolling Interest [Member]	Duke Energy Carolinas [Member]	Duke Energy Carolinas [Member] Members Equity [Member]	Duke Energy Carolinas [Member] Net Gains (Losses) on Cash Flow Hedges [Member]	Progress Energy [Member]		Progress Energy [Member] Additional Paid-in Capital [Member]	Progress Energy [Member] Retained Earnings [Member]		Progress Energy [Member] Net Gains (Losses) on Cash Flow Hedges [Member]	Progress Energy [Member] Net Unrealized Gains (Losses) on Available for Sale Securities [Member]	Progress Energy [Member] Pension and OPEB Adjustments [Member]	Progress Energy [Member] Common Stockholders' Equity [Member]		Progress Energy [Member] Noncontrolling Interest [Member]	Duke Energy Progress [Member]	Duke Energy Florida [Member]	Duke Energy Florida [Member] Members Equity [Member]	Duke Energy Florida [Member] Net Unrealized Gains (Losses) on Available for Sale Securities [Member]	Duke Energy Ohio [Member]	Duke Energy Ohio [Member] Common Stock [Member]	Duke Energy Ohio [Member] Additional Paid-in Capital [Member]	Duke Energy Ohio [Member] Retained Earnings [Member]	Duke Energy Indiana [Member]	Duke Energy Indiana [Member] Common Stock [Member]	Duke Energy Indiana [Member] Additional Paid-in Capital [Member]	Duke Energy Indiana [Member] Retained Earnings [Member]	Duke Energy Indiana [Member] Members Equity [Member]	Duke Energy Indiana [Member] Net Gains (Losses) on Cash Flow Hedges [Member]	Piedmont Natural Gas [Member]	Piedmont Natural Gas [Member] Common Stock [Member]	Piedmont Natural Gas [Member] Retained Earnings [Member]	Piedmont Natural Gas [Member] Net Gains (Losses) on Cash Flow Hedges [Member]
Beginning Balance at Dec. 31, 2015	$ 39,771		$ 1	$ 37,968	$ 2,564		$ (692)	$ (50)	$ (3)	$ (61)	$ 39,727		$ 44				$ 12,853		$ 8,092	$ 4,831		$ (31)		$ (17)	$ 12,875		$ (22)
Beginning Balance, in shares at Dec. 31, 2015			688,000,000
Beginning Balance (member's equity) at Dec. 31, 2015														$ 11,606	$ 11,617	$ (11)												$ 7,059	$ 5,121	$ 5,121
Beginning Balance (parent) at Dec. 31, 2015																																$ 2,784	$ 762	$ 2,720	$ (698)	$ 3,836	$ 1	$ 1,384	$ 2,450		$ 1	$ 1,458	$ 728	$ 731	$ (1)
Net income	2,392				2,379						2,379		13				935			927					927		8
Net income (attributable to parent)	2,379													1,026	1,026		927											539	487	487		171			171	309				$ 309		94		94
Other comprehensive income (loss)	88						92	(16)	7	2	85		3	1		1	8					4	$ 2	2	8				2		$ 2					(1)					$ (1)	1			1
Common stock issuances, including dividend reinvestment and employee benefits, shares			1,000,000
Common stock issuances, including dividend reinvestment and employee benefits	29			29							29																															121	121
Common stock dividends	(1,731)				(1,731)						(1,731)																															(87)		(87)
Distributions to noncontrolling interest in subsidiaries	(3)												(3)				(1)										(1)
Distributions/dividends to parent														(1,800)	(1,800)		(1,075)			(1,075)					(1,075)			(301)	(774)	(774)		(25)		(25)		(149)				(149)
Other														(3)	(3)		3		4						4		(1)		3	3		9			9		$ (1)	$ (1,384)	$ (2,450)	3,835
Ending Balance at Sep. 30, 2016	40,546		$ 1	37,997	3,212		$ (600)	(66)	4	(59)	40,489		57				12,723		8,096	4,683		(27)	2	(15)	12,739		(16)
Ending Balance, in shares at Sep. 30, 2016			689,000,000
Ending Balance (member's equity) at Sep. 30, 2016														10,830	10,840	(10)												7,297	4,839	4,837	2					3,995				3,995
Ending Balance (parent) at Sep. 30, 2016																																$ 2,939	762	2,695	(518)							$ 1,587	849	738	$ 0
Beginning Balance at Dec. 31, 2016	$ 41,041		$ 1	38,741	2,384			(20)	(1)	(72)	41,033		8				$ 11,807		8,094	3,764		(23)	1	(16)	11,820		(13)
Beginning Balance, in shares at Dec. 31, 2016	700,000,000		700,000,000														100															90,000,000										100
Beginning Balance (member's equity) at Dec. 31, 2016														10,772	10,781	(9)												7,358	4,900	4,899	1					4,067				4,067
Beginning Balance (parent) at Dec. 31, 2016	$ 41,033																$ 11,820															$ 2,996	762	2,695	(461)							$ 1,672	860	812
Net income	2,361				2,356						2,356		5				821			814					814		7
Net income (attributable to parent)	2,356													1,009	1,009		814											547	368	368		127			127	318				318		76		76
Other comprehensive income (loss)	13							1	10	2	13			1		1	12					4	3	5	12				3		3
Common stock issuances, including dividend reinvestment and employee benefits	33			33							33
Common stock dividends	(1,825)				(1,825)						(1,825)
Distributions to noncontrolling interest in subsidiaries	(2)												(2)
Distributions/dividends to parent														(625)	(625)		(672)	[1]		(672)	[1]				(672)	[1]		(125)				$ (25)		(25)		(300)				(300)
Equitization of certain notes payable to affiliates																	1,047		1,047						1,047
Other	21	[2]			21	[2]					21	[2]		(1)	(1)		2		2						2				3	3												$ (149)		(149)
Ending Balance at Sep. 30, 2017	$ 41,642		$ 1	$ 38,774	$ 2,936			$ (19)	$ 9	$ (70)	$ 41,631		$ 11				$ 13,017		$ 9,143	$ 3,906		$ (19)	$ 4	$ (11)	$ 13,023		$ (6)
Ending Balance, in shares at Sep. 30, 2017	700,000,000		700,000,000														100															90,000,000										100
Ending Balance (member's equity) at Sep. 30, 2017														$ 11,156	$ 11,164	$ (8)												$ 7,780	$ 5,274	$ 5,270	$ 4					$ 4,085				$ 4,085
Ending Balance (parent) at Sep. 30, 2017	$ 41,631																$ 13,023															$ 3,098	$ 762	$ 2,670	$ (334)							$ 1,599	$ 860	$ 739

[1] Includes a $547 million non-cash dividend related to a legal entity restructuring.

[2] Cumulative-effect adjustment due to implementation of a new accounting standard related to stock-based compensation and the associated income taxes. See Note 1 for more information.