Business Segment Information Business Segment Information (Restructuring Costs) (Details) - Entergy Wholesale Commodities [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 71.0	$ 91.0	$ 139.0
Paid in cash	55.0	141.0	43.0
Restructuring Reserve	159.0	143.0	193.0	$ 97.0
Employee Retention and Severances Expenses and Other Benefits-Related Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs	71.0	91.0	139.0
Paid in cash	55.0	141.0	43.0
Restructuring Reserve	145.0	129.0	179.0	83.0
Economic Development Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs	0.0	0.0	0.0
Paid in cash	0.0	0.0	0.0
Restructuring Reserve	$ 14.0	$ 14.0	$ 14.0	$ 14.0