Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 718
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-Section S99
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The amount of expense, net of income tax, recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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Stock-Based Compensation (Schedule of Stock-Based Compensation Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Oct. 31, 2016	Dec. 31, 2015	Oct. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	$ 43	$ 35	$ 10	$ 38	$ 10
Pretax stock-based compensation expense	68	55	16	61	14
Tax benefit associated with stock-based compensation expense	25	20	$ 6	23	$ 4
Stock-based compensation costs capitalized	4	2		3
Restricted Stock Units Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pretax stock-based compensation expense	41	36		38
Performance Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pretax stock-based compensation expense	27	19		23
Duke Energy Carolinas [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	15	12		14
Progress Energy [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	16	12		14
Duke Energy Progress [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	10	7		9
Duke Energy Florida [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	6	5		5
Duke Energy Ohio [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	3	2		2
Duke Energy Indiana [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	4	$ 3		$ 4
Piedmont Natural Gas [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense, Net of Tax	$ 3