Business Segment Information Business Segment Information (Restructuring Costs) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Restructuring Charges	$ 43	$ 23	$ 103	$ 89
Restructuring Reserve	200	73	200	73	$ 157	$ 97	$ 57	$ 91
Payments for Restructuring			0	100
Employee Retention and Severances Expenses and Other Benefits-Related Costs [Member]
Segment Reporting Information [Line Items]
Restructuring Charges	43	23	103	89
Restructuring Reserve	186	59	186	59	143	83	36	70
Payments for Restructuring			0	100
Economic Development Costs [Member]
Segment Reporting Information [Line Items]
Restructuring Charges	0	0	0	0
Restructuring Reserve	14	14	14	14	$ 14	$ 14	$ 21	$ 21
Payments for Restructuring			0	0
Entergy Wholesale Commodities [Member]
Segment Reporting Information [Line Items]
Restructuring Reserve, Settled without Cash	0	(7)	0	(7)
Entergy Wholesale Commodities [Member] | Employee Retention and Severances Expenses and Other Benefits-Related Costs [Member]
Segment Reporting Information [Line Items]
Restructuring Reserve, Settled without Cash	0	0	0	0
Entergy Wholesale Commodities [Member] | Economic Development Costs [Member]
Segment Reporting Information [Line Items]
Restructuring Reserve, Settled without Cash	$ 0	$ (7)	$ 0	$ (7)