Business Segment Information Business Segment Information (Restructuring Costs) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Employee Retention and Severances Expenses and Other Benefits-Related Costs [Member]
Segment Reporting Information [Line Items]
Restructuring Charges	$ 34
Entergy Wholesale Commodities [Member]
Segment Reporting Information [Line Items]
Restructuring Charges	34	$ 26
Restructuring Reserve	227	123	$ 193	$ 97
Entergy Wholesale Commodities [Member] | Employee Retention and Severances Expenses and Other Benefits-Related Costs [Member]
Segment Reporting Information [Line Items]
Restructuring Charges	34	26
Restructuring Reserve	213	109	179	83
Entergy Wholesale Commodities [Member] | Economic Development Costs [Member]
Segment Reporting Information [Line Items]
Restructuring Charges	0	0
Restructuring Reserve	$ 14	$ 14	$ 14	$ 14