Consolidated Statements of 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]	Duke Energy Carolinas [Member] Net Unrealized Gains (Losses) on Available-for-Sale Securities [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 Progress [Member] Common Stock [Member]	Duke Energy Progress [Member] Retained Earnings [Member]	Duke Energy Progress [Member] Members Equity [Member]	Duke Energy Florida [Member]	Duke Energy Florida [Member] Common Stock [Member]	Duke Energy Florida [Member] Retained Earnings [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 (Attributable to Parent) at Oct. 31, 2014																																														$ 1,309	$ 637	$ 672
Net Income Attributable to Parent																																														137		137
Other comprehensive income (loss), net of tax																																														(1)			$ (1)
Common stock issuances, including dividend reinvestment and employee benefits																																														85	85
Expenses from issuance of common stock																																														(1)	(1)
Common stock dividends																																														(103)		(103)
Ending Balance (Attributable to Parent) at Oct. 31, 2015																																														1,426	721	706	(1)
Beginning Balance (parent) at Dec. 31, 2014	$ 40,899	$ 1	$ 39,405	$ 2,012		$ (439)		$ (59)	$ 3	$ (48)	$ 40,875	$ 24						$ 11,176	$ 7,467	$ 3,782		$ (35)	$ 1	$ (7)	$ 11,208	$ (32)
Beginning Members' Equity at Dec. 31, 2014														$ 10,924	$ 10,937	$ (12)	$ (1)
Beginning Balance (Attributable to Parent) at Dec. 31, 2014																											$ 5,867	$ 2,159	$ 3,708		$ 5,222	$ 1,762	$ 3,460			$ 4,674	$ 762	$ 4,782	$ (870)	$ 3,848	$ 1	$ 1,384	$ 2,460		$ 3
Balance (in shares) at Dec. 31, 2014		707,000,000
Net income	2,831			2,816							2,816	15						1,062		1,051					1,051	11
Net Income Attributable to Parent	2,816													1,081	1,081			1,051									566		355	$ 211	599		351	$ 248		172			172	316			316
Other comprehensive income (loss), net of tax	(274)					(253)		9	(6)	(13)	(263)	(11)		2		1	$ 1	(7)				4	(1)	(10)	(7)															(2)					(2)
Common stock issuances, including dividend reinvestment and employee benefits (in shares)		1,000,000
Common stock issuances, including dividend reinvestment and employee benefits	$ 63		63								63
Stock repurchase, shares	(19,800,000)	(20,000,000)
Stock repurchase	$ (1,500)		(1,500)								(1,500)
Common stock dividends	(2,254)			(2,254)							(2,254)																				(350)		(350)
Distributions/Dividends to parent														(401)	(401)																(350)			(350)		(150)		(150)		(326)			(326)
Distributions to noncontrolling interest in subsidiaries	(9)											(9)						(4)								(4)
Capital contribution from parent																		625	625						625		626			626
Distribution of membership interest of Duke Energy SAM, LLC to parent																																				(1,912)		(1,912)
Other	15			(10)							(10)	25	[1]					1		(2)					(2)	3		$ (2,159)	$ (4,063)	6,222		$ (1,762)	$ (3,461)	5,223
Balance (in shares) at Dec. 31, 2015		688,000,000
Ending Balance (parent) 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)
Ending member's equity at Dec. 31, 2015														11,606	11,617	(11)											7,059			7,059	5,121			5,121
Ending Balance (Attributable to Parent) at Dec. 31, 2015																																				2,784	762	2,720	(698)	3,836	1	1,384	2,450		1
Beginning Balance (Attributable to Parent) at Oct. 31, 2015																																														1,426	721	706	(1)
Net Income Attributable to Parent																																														193		193
Other comprehensive income (loss), net of tax																																														1			$ 1
Common stock issuances, including dividend reinvestment and employee benefits																																														139	139
Common stock dividends																																														(114)		(114)
Ending Balance (Attributable to Parent) at Oct. 31, 2016																																														$ 1,645	860	785
Beginning Balance (Attributable to Parent) at Dec. 31, 2015																																				2,784	762	2,720	(698)	3,836	1	1,384	2,450		1
Net income	2,170			2,152							2,152	18						1,041		1,031					1,031	10
Net Income Attributable to Parent	2,152													1,166	1,166			1,031									599			599	551			551		228			228	381				$ 381
Other comprehensive income (loss), net of tax	715					$ 692	[2]	30	2	(11)	713	2		2		2		10				8	1	1	10						1				$ 1					(1)					$ (1)
Common stock issuances, including dividend reinvestment and employee benefits (in shares)		12,000,000
Common stock issuances, including dividend reinvestment and employee benefits	773		773								773
Common stock dividends	(2,332)			(2,332)							(2,332)
Distributions/Dividends to parent														(2,000)	(2,000)			(2,098)		(2,098)					(2,098)		(300)			(300)	(775)			(775)		(25)		(25)		(149)				(149)
Distributions to noncontrolling interest in subsidiaries	(6)											(6)						(1)								(1)
Capital contribution from parent																																				$ 9			9
Other	$ (50)											(50)	[3]	(2)	(2)			$ 2	2						2						2			2							$ (1)	$ (1,384)	$ (2,450)	3,835
Balance (in shares) at Dec. 31, 2016	700,000,000	700,000,000																100																		90,000,000										100
Ending Balance (parent) 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)
Ending member's equity at Dec. 31, 2016														10,772	10,781	(9)											7,358			7,358	4,900			4,899	1					4,067				4,067
Ending Balance (Attributable to Parent) at Dec. 31, 2016	$ 41,033																	$ 11,820																		$ 2,996	762	2,695	(461)							$ 1,672	860	812
Beginning Balance (Attributable to Parent) at Oct. 31, 2016																																														1,645	860	785
Net Income Attributable to Parent																																														54		54
Distributions/Dividends to parent																																														$ (27)		(27)
Balance (in shares) at Dec. 31, 2016	700,000,000	700,000,000																100																		90,000,000										100
Ending Balance (parent) 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)
Ending member's equity at Dec. 31, 2016														10,772	10,781	(9)											7,358			7,358	4,900			4,899	1					4,067				4,067
Ending Balance (Attributable to Parent) at Dec. 31, 2016	41,033																	11,820																		$ 2,996	762	2,695	(461)							$ 1,672	860	812
Net income	3,064			3,059							3,059	5						1,268		1,258					1,258	10
Net Income Attributable to Parent	3,059													1,214	1,214			1,258									715			715	712			712		192			192	354				354		139
Other comprehensive income (loss), net of tax	26							10	13	3	26			2		2		13				5	4	4	13						3				3
Common stock issuances, including dividend reinvestment and employee benefits	51		51								51
Common stock dividends	(2,450)			(2,450)							(2,450)
Distributions/Dividends to parent														(625)	(625)			(672)		(672)	[4]				(672)		(124)			(124)						$ (25)		(25)		(300)				(300)
Distributions to noncontrolling interest in subsidiaries	(2)											(2)
Equitization of certain notes payable to affiliates																		1,047	1,047						1,047
Other	$ 7			20	[5]						20	(13)	[5]	(2)	(2)			$ 2	2						2						3			3												$ (149)		(149)
Balance (in shares) at Dec. 31, 2017	700,000,000	700,000,000																100																		90,000,000										100
Ending Balance (parent) at Dec. 31, 2017	$ 41,737	$ 1	$ 38,792	$ 3,013				$ (10)	$ 12	$ (69)	$ 41,739	$ (2)						$ 13,465	$ 9,143	$ 4,350		$ (18)	$ 5	$ (12)	$ 13,468	$ (3)
Ending member's equity at Dec. 31, 2017														$ 11,361	$ 11,368	$ (7)											$ 7,949			$ 7,949	$ 5,618			$ 5,614	$ 4					$ 4,121				$ 4,121
Ending Balance (Attributable to Parent) at Dec. 31, 2017	$ 41,739																	$ 13,468																		$ 3,163	$ 762	$ 2,670	$ (269)							$ 1,662	$ 860	$ 802

[1] Noncontrolling Interests amount is primarily related to the acquisitions of a majority interest in a provider of energy management systems and services for commercial customers and a solar company.

[2] Foreign Currency Translation Adjustments amount includes $620 million of cumulative adjustment realized as a result of the sale of the Latin American generation business. See Note 2 to the Consolidated Financial Statements.

[3] Noncontrolling Interests amount is primarily related to the sale of the Latin American generation business. See Note 2 to the Consolidated Financial Statements.

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

[5] Retained Earnings relates to a cumulative-effect adjustment due to implementation of a new accounting standard related to stock-based compensation and the associated income taxes. See Note 1 to the Consolidated Financial Statements for additional information. Noncontrolling Interests relates to the purchase of remaining interest in REC Solar.