Transactions With Affiliates (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Entergy Arkansas [Member]
Intercompany revenues	$ 105,200,000	$ 117,500,000	$ 104,300,000
Intercompany operating expenses	515,500,000	534,000,000.0	471,900,000
Intercompany interest and investment income	0	400,000	400,000
Entergy Louisiana [Member]
Intercompany revenues	280,500,000	277,800,000	299,000,000.0
Intercompany operating expenses	661,500,000	665,400,000	627,800,000
Intercompany interest and investment income	127,700,000	128,500,000	128,200,000
Entergy Mississippi [Member]
Intercompany revenues	1,200,000	1,400,000	2,500,000
Intercompany operating expenses	283,300,000	306,700,000	266,800,000
Intercompany interest and investment income	100,000	400,000	0
Entergy New Orleans [Member]
Intercompany revenues	0	0	0
Intercompany operating expenses	266,000,000.0	292,100,000	256,400,000
Intercompany interest and investment income	0	0	0
Entergy Texas [Member]
Intercompany revenues	40,400,000	51,600,000	58,800,000
Intercompany operating expenses	260,300,000	255,000,000.0	240,200,000
Intercompany interest and investment income	0	400,000	200,000
System Energy [Member]
Intercompany revenues	520,700,000	584,100,000	456,700,000
Intercompany operating expenses	177,400,000	156,200,000	176,500,000
Intercompany interest and investment income	200,000	1,000,000.0	1,200,000
EWO Marketing, LLC [Member] | RS Cogen [Member]
Intercompany operating expenses	$ 26,000,000	$ 24,500,000	$ 24,000,000