Income Taxes Income Taxes (Tax Cuts and Jobs Act) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Reduction to Regulatory Liability due to return of unprotected excess ADIT	$ 74	$ 273
Entergy Arkansas [Member]
Net Regulatory Liabilities for Income Taxes	467	487
Protected Excess ADIT	490	490
Unprotected Excess Accumulated Deferred Income Taxes	11	9
Reduction to Regulatory Liability due to return of unprotected excess ADIT	8	126
Entergy Louisiana [Member]
Net Regulatory Liabilities for Income Taxes	479	531
Protected Excess ADIT	721	797
Unprotected Excess Accumulated Deferred Income Taxes	223	242
Reduction to Regulatory Liability due to return of unprotected excess ADIT	31	39
Entergy Mississippi [Member]
Net Regulatory Liabilities for Income Taxes	224	237
Protected Excess ADIT	248	261
Entergy New Orleans [Member]
Net Regulatory Liabilities for Income Taxes	59	59
Protected Excess ADIT	61	62
Unprotected Excess Accumulated Deferred Income Taxes	3	9
Reduction to Regulatory Liability due to return of unprotected excess ADIT	6	14
Entergy Texas [Member]
Net Regulatory Liabilities for Income Taxes	205	253
Protected Excess ADIT	215	228
Unprotected Excess Accumulated Deferred Income Taxes	54	83
Reduction to Regulatory Liability due to return of unprotected excess ADIT	29	87
System Energy [Member]
Net Regulatory Liabilities for Income Taxes	152	143
Protected Excess ADIT	173	186
Unprotected Excess Accumulated Deferred Income Taxes	16	0
Reduction to Regulatory Liability due to return of unprotected excess ADIT	$ 0	$ 7