Income Taxes Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended	9 Months Ended
	Jun. 30, 2016	Sep. 30, 2016	Dec. 31, 2015
Regulatory Liability, Noncurrent		$ 1,525,897	$ 1,414,898
Income tax benefit resulting from 2010-2011 IRS audit associated with Act 55 financing	$ 63,500
Reduction in income tax expense related to permanent difference for nuclear decommissioning liability, net of unrecognized tax benefits		238,000
Entergy Arkansas [Member]
Regulatory Liability, Noncurrent		292,545	242,913
Entergy Louisiana [Member]
Proceeds received from LURC related to Act 55 financing not taxable	148,600
Regulatory Liability, Noncurrent		849,470	818,623
Unrecognized Tax Benefits	564,700		796,900
Income tax benefit resulting from 2010-2011 IRS audit associated with Act 55 financing	61,600
Income tax benefit resulting from 2010-2011 IRS audit related to Vidalia purchased power agreement	74,500
Regulatory liability for customer savings associated with Act 55 financing	16,100
Regulatory liability for customer savings associated with Act 55 financing, net of tax	$ 9,900
System Energy [Member]
Regulatory Liability, Noncurrent		$ 365,302	$ 337,424