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	1,211				1,203						1,203		8				486		481				481	5
Net income (attributable to parent)	1,203													532	532		481								268	281	281		82			82	180				$ 180		106		106
Other comprehensive income (loss)	93						103	(23)	7	2	89		4	1		1	6			3	$ 1	2	6			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	16			16							16																												12	12
Common stock dividends	(1,140)				(1,140)						(1,140)						(651)		(651)				(651)						(25)		(25)								(55)		(55)
Distributions to parent														(1,200)	(1,200)											(649)	(649)						(149)				(149)
Distributions to noncontrolling interest in subsidiaries	(3)												(3)				(1)							(1)
Other																																		$ (1)	$ (1,384)	$ (2,450)	3,835
Ending Balance at Jun. 30, 2016	39,948		$ 1	37,984	2,627		$ (589)	(73)	4	(59)	39,895		53				12,693	8,092	4,661	(28)	1	(15)	12,711	(18)
Ending Balance, in shares at Jun. 30, 2016			689,000,000
Ending Balance (member's equity) at Jun. 30, 2016														10,939	10,949	(10)									7,327	4,754	4,753	1					3,866				3,866
Ending Balance (parent) at Jun. 30, 2016																													$ 2,841	762	2,695	(616)							$ 1,521	740	782	$ (1)
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	1,406				1,402						1,402		4				478		473				473	5
Net income (attributable to parent)	1,402													543	543		473								301	248	248		72			72	197				197		87		87
Other comprehensive income (loss)	11							1	8	2	11			1		1	10			6	2	2	10			2		2
Common stock issuances, including dividend reinvestment and employee benefits	17			17							17
Common stock dividends	(1,200)				(1,200)						(1,200)																		$ (25)		(25)
Distributions to parent														(375)	(375)																		(150)				(150)
Distributions to noncontrolling interest in subsidiaries	(2)												(2)
Other	21	[1]			21	[1]					21	[1]		(2)	(2)		2	2					2			2	2												$ (149)		(149)
Ending Balance at Jun. 30, 2017	$ 41,294		$ 1	$ 38,758	$ 2,607			$ (19)	$ 7	$ (70)	$ 41,284		$ 10				$ 12,297	$ 8,096	$ 4,237	$ (17)	$ 3	$ (14)	$ 12,305	$ (8)
Ending Balance, in shares at Jun. 30, 2017	700,000,000		700,000,000														100												90,000,000										100
Ending Balance (member's equity) at Jun. 30, 2017														$ 10,939	$ 10,947	$ (8)									$ 7,659	$ 5,152	$ 5,149	$ 3					$ 4,114				$ 4,114
Ending Balance (parent) at Jun. 30, 2017	$ 41,284																$ 12,305												$ 3,043	$ 762	$ 2,670	$ (389)							$ 1,610	$ 860	$ 750

[1] 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.