Transactions With Affiliates (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Entergy Arkansas [Member]
Intercompany revenues		$ 127.9	$ 131.2	$ 349.9
Intercompany operating expenses	[1]	508.5	596.6	656.1
Entergy Arkansas [Member] | Entergy Power [Member]
Intercompany operating expenses				3.3
Entergy Louisiana [Member]
Intercompany revenues		420.2	440.2	329.5
Intercompany operating expenses	[2]	929.4	1,027.6	1,171.9
Intercompany interest and investment income		133.6	117.9	105.7
Entergy Louisiana [Member] | Entergy Power [Member]
Intercompany operating expenses				8.1
Entergy Louisiana [Member] | RS Cogen [Member]
Intercompany operating expenses				3.2
Entergy Mississippi [Member]
Intercompany revenues		86.0	169.8	107.3
Intercompany operating expenses		331.8	367.6	399.0
Entergy New Orleans [Member]
Intercompany revenues		66.1	80.1	28.1
Intercompany operating expenses	[3]	278.4	249.5	288.7
Entergy New Orleans [Member] | Entergy Power [Member]
Intercompany operating expenses				8.0
Entergy Texas [Member]
Intercompany revenues		259.1	316.1	369.4
Intercompany operating expenses		413.7	445.3	418.1
System Energy [Member]
Intercompany revenues		632.4	664.4	735.1
Intercompany operating expenses		$ 155.1	$ 156.7	$ 175.2

[1] Includes power purchased from Entergy Power of $3.3 million in 2013. The contract with Entergy Power expired in May 2013.

[2] Includes power purchased from RS Cogen of $3.2 million in 2013 and power purchased from Entergy Power of $8.1 million in 2013. The contract with Entergy Power expired in May 2013.

[3] Includes power purchased from Entergy Power of $8 million in 2013. The contract with Entergy Power expired in May 2013.