Acquisitions Acquisitions (Narrative) (Details) $ in Thousands	1 Months Ended	3 Months Ended
	Mar. 31, 2016 USD ($) MW	Mar. 31, 2016 USD ($) MW	Mar. 31, 2015 USD ($)
Payments to Acquire Property, Plant, and Equipment		$ (947,778)	$ 0
Union Power Station [Member]
Capacity Per Power Block | MW	495	495
Payments to Acquire Property, Plant, and Equipment	$ (948,000)
Capacity Of Power Plant Unit | MW	1,980
Entergy Arkansas [Member]
Payments to Acquire Property, Plant, and Equipment	$ (237,000)	$ (236,947)	0
Entergy Arkansas [Member] | Union Power Station [Member]
Percentage of Undivided Ownership Interest	25.00%	25.00%
Payments to Acquire Property, Plant, and Equipment	$ (236,944)
Power Blocks Purchased	1	1
Entergy Louisiana [Member]
Payments to Acquire Property, Plant, and Equipment	$ (474,000)	$ (473,888)	0
Entergy Louisiana [Member] | Union Power Station [Member]
Percentage of Undivided Ownership Interest	50.00%	50.00%
Payments to Acquire Property, Plant, and Equipment	$ (473,888)
Power Blocks Purchased	2	2
Entergy New Orleans [Member]
Payments to Acquire Property, Plant, and Equipment	$ (237,000)	$ (236,944)	$ 0
Entergy New Orleans [Member] | Union Power Station [Member]
Percentage of Undivided Ownership Interest	25.00%	25.00%
Payments to Acquire Property, Plant, and Equipment	$ (236,944)
Power Blocks Purchased	1	1