Leases (Rent Expenses) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($)
Rent Expense	$ 47.8
Entergy Arkansas [Member]
Rent Expense	6.2
Entergy Louisiana [Member]
Rent Expense	20.2
Entergy Mississippi [Member]
Rent Expense	4.6
Entergy New Orleans [Member]
Rent Expense	2.5
Entergy Texas [Member]
Rent Expense	3.1
System Energy [Member]
Rent Expense	$ 1.9