DECOMMISSIONING TRUST FUNDS (Entergy Corporation, Entergy Arkansas, Entergy Louisiana, and System Energy) (Schedule of Investments Classified by Contractual Maturity Date) (Details) - USD ($) $ in Millions	Sep. 30, 2026	Dec. 31, 2025
Debt Securities, Available-for-Sale, Fair Value, Fiscal Year Maturity [Abstract]
Less than 1 year	$ 47.0	$ 31.0
1 year - 5 years	779.0	649.0
5 years - 10 years	703.0	645.0
10 years - 15 years	170.0	188.0
15 years - 20 years	312.0	218.0
20 years+	399.0	471.0
Fair value	2,410.0	2,202.0
ENTERGY ARKANSAS, LLC
Debt Securities, Available-for-Sale, Fair Value, Fiscal Year Maturity [Abstract]
Less than 1 year	23.1	27.7
1 year - 5 years	208.1	140.2
5 years - 10 years	259.0	256.8
10 years - 15 years	51.7	69.1
15 years - 20 years	98.4	61.4
20 years+	33.7	58.8
Fair value	674.0	614.0
ENTERGY LOUISIANA, LLC
Debt Securities, Available-for-Sale, Fair Value, Fiscal Year Maturity [Abstract]
Less than 1 year	13.1	0.9
1 year - 5 years	307.9	259.0
5 years - 10 years	289.1	227.7
10 years - 15 years	91.6	93.6
15 years - 20 years	145.8	110.9
20 years+	235.1	300.5
Fair value	1,082.6	992.6
SYSTEM ENERGY RESOURCES, INC.
Debt Securities, Available-for-Sale, Fair Value, Fiscal Year Maturity [Abstract]
Less than 1 year	10.3	2.2
1 year - 5 years	263.3	249.8
5 years - 10 years	155.0	160.3
10 years - 15 years	26.4	25.5
15 years - 20 years	68.0	46.2
20 years+	130.6	111.0
Fair value	$ 653.6	$ 595.0