Revolving Credit Facilities, Lines Of Credit, Short-Term Borrowings, And Long-Term Debt Revolving Credit Facilities, Lines Of Credit, Short-Term Borrowings, And Long-Term Debt (Uncommitted Standby Letter of Credit Facilities to Support MISO Obligations) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Entergy Arkansas [Member]
Letters of Credit Outstanding, Amount	$ 0.4
Entergy Mississippi [Member]
Letters of Credit Outstanding, Amount	0.4	$ 0.2
Entergy Louisiana [Member]
Letters of Credit Outstanding, Amount	0.2	0.3
Entergy New Orleans [Member]
Letters of Credit Outstanding, Amount	0.1	0.2
Entergy Texas [Member]
Letters of Credit Outstanding, Amount		$ 0.5
Credit Facility Of Twenty Five Million [Member] | Entergy Arkansas [Member]
Uncommitted Credit Facility	$ 25.0
Letter of Credit Fee, Percentage	0.78%
Letters of Credit Outstanding, Amount	$ 1.0
Credit Facility of Fifty Million [Member] | Entergy Texas [Member]
Uncommitted Credit Facility	$ 50.0
Letter of Credit Fee, Percentage	0.70%
Letters of Credit Outstanding, Amount	$ 30.2
Credit Facility of Fifteen Million [Member] | Entergy New Orleans [Member]
Uncommitted Credit Facility	$ 15.0
Letter of Credit Fee, Percentage	1.00%
Letters of Credit Outstanding, Amount	$ 2.0
Credit Facility Of One Hundred Twenty Five Million [Member] | Entergy Louisiana [Member]
Uncommitted Credit Facility	$ 125.0
Letter of Credit Fee, Percentage	0.78%
Letters of Credit Outstanding, Amount	$ 12.8
Credit Facility of Sixty Five Million [Member] | Entergy Mississippi [Member]
Uncommitted Credit Facility	$ 65.0
Letter of Credit Fee, Percentage	0.78%
Letters of Credit Outstanding, Amount	$ 1.0