Variable Interest Entities (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Mar. 31, 2016	Sep. 30, 2017	Sep. 30, 2016
Waterford Three [Member] | Entergy Louisiana [Member]
Variable Interest Entity [Line Items]
Payments on lease, including interest			$ 9.2
Percentage In Power Plant Previously Owned By VIE				9.30%
Grand Gulf [Member] | System Energy [Member]
Variable Interest Entity [Line Items]
Payments on lease, including interest	$ 8.6	$ 8.6		$ 17.2	$ 17.2
Percentage in power plant owned by VIE				11.50%