Revenue Recognition (Allowance for Doubtful Accounts) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Allowance for Doubtful Other Receivables, Current	$ 31.5	$ 119.0	$ 68.6	$ 117.7
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease)	(5.9)	3.2
Accounts Receivable, Allowance for Credit Loss, Writeoff	(45.3)	(3.8)
Accounts Receivable, Allowance for Credit Loss, Recovery	14.1	1.9
Entergy Arkansas [Member]
Disaggregation of Revenue [Line Items]
Allowance for Doubtful Other Receivables, Current	6.5	21.2	13.1	18.3
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease)	3.7	2.4
Accounts Receivable, Allowance for Credit Loss, Writeoff	(14.4)	(0.1)
Accounts Receivable, Allowance for Credit Loss, Recovery	4.1	0.6
Entergy Louisiana [Member]
Disaggregation of Revenue [Line Items]
Allowance for Doubtful Other Receivables, Current	11.1	46.6	29.2	45.7
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease)	(6.1)	2.3
Accounts Receivable, Allowance for Credit Loss, Writeoff	(17.5)	(2.1)
Accounts Receivable, Allowance for Credit Loss, Recovery	5.5	0.7
Entergy Mississippi [Member]
Disaggregation of Revenue [Line Items]
Allowance for Doubtful Other Receivables, Current	3.4	16.8	7.2	19.5
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease)	(0.9)	(2.2)
Accounts Receivable, Allowance for Credit Loss, Writeoff	(4.1)	(0.8)
Accounts Receivable, Allowance for Credit Loss, Recovery	1.2	0.3
Entergy New Orleans [Member]
Disaggregation of Revenue [Line Items]
Allowance for Doubtful Other Receivables, Current	7.7	19.4	13.3	17.4
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease)	(2.4)	1.8
Accounts Receivable, Allowance for Credit Loss, Writeoff	(5.4)	0.0
Accounts Receivable, Allowance for Credit Loss, Recovery	2.2	0.2
Entergy Texas [Member]
Disaggregation of Revenue [Line Items]
Allowance for Doubtful Other Receivables, Current	2.8	15.0	$ 5.8	$ 16.8
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease)	(0.2)	(1.1)
Accounts Receivable, Allowance for Credit Loss, Writeoff	(3.9)	(0.8)
Accounts Receivable, Allowance for Credit Loss, Recovery	$ 1.1	$ 0.1