Transactions With Affiliates (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Entergy Arkansas [Member]
Intercompany revenues	$ 117,500,000	$ 104,300,000	$ 127,800,000
Intercompany operating expenses	534,000,000.0	471,900,000	510,200,000
Intercompany interest and investment income	400,000	400,000	0
Entergy Louisiana [Member]
Intercompany revenues	277,800,000	299,000,000.0	282,400,000
Intercompany operating expenses	665,400,000	627,800,000	619,500,000
Intercompany interest and investment income	128,500,000	128,200,000	128,000,000.0
Entergy Mississippi [Member]
Intercompany revenues	1,400,000	2,500,000	1,700,000
Intercompany operating expenses	306,700,000	266,800,000	310,500,000
Intercompany interest and investment income	400,000	0	0
Entergy New Orleans [Member]
Intercompany revenues	0	0	0
Intercompany operating expenses	292,100,000	256,400,000	286,100,000
Intercompany interest and investment income	0	0	200,000
Entergy Texas [Member]
Intercompany revenues	51,600,000	58,800,000	57,900,000
Intercompany operating expenses	255,000,000.0	240,200,000	234,600,000
Intercompany interest and investment income	400,000	200,000	0
System Energy [Member]
Intercompany revenues	584,100,000	456,700,000	633,500,000
Intercompany operating expenses	156,200,000	176,500,000	197,000,000.0
Intercompany interest and investment income	1,000,000.0	1,200,000	900,000
EWO Marketing, LLC [Member] | RS Cogen [Member]
Intercompany operating expenses	$ 24,500,000	$ 24,000,000	$ 24,600,000