Decommissioning Trust Funds (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Jan. 01, 2018
Decommissioning Trust Funds [Abstract]
Accumulated Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, after Tax						$ (632,617)
Amortized cost of debt securities	$ 2,653,000		$ 2,653,000		$ 2,539,000
Average coupon rate of debt securities	3.31%		3.31%
Average duration of debt securities, years			6 years 281 days
Average maturity of debt securities, years			10 years 22 days
Proceeds from the dispositions of debt securities	$ 710,000	$ 949,000	$ 1,801,000	$ 1,463,000
Gains from dispositions of debt securities, gross	1,000	61,000	2,000	70,000
Losses from dispositions of debt securities, gross	15,000	2,000	22,000	7,000
Equity Securities, FV-NI, Unrealized Gain	100,000		33,000
Equity Securities [Member]
Decommissioning Trust Funds [Abstract]
Deferred taxes on unrealized gains/(losses) recorded in OCI for non-regulated decommissioning trusts					472,000
Debt Securities [Member]
Decommissioning Trust Funds [Abstract]
Deferred taxes on unrealized gains/(losses) recorded in OCI for non-regulated decommissioning trusts			(5,000)		7,000
Entergy Arkansas [Member]
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	$ 351,200		$ 351,200		349,100
Average coupon rate of debt securities	2.64%		2.64%
Average duration of debt securities, years			4 years 263 days
Average maturity of debt securities, years			6 years 139 days
Proceeds from the dispositions of debt securities	$ 86,500	131,300	$ 121,400	167,300
Gains from dispositions of debt securities, gross	10	11,200	100	11,700
Losses from dispositions of debt securities, gross	2,300	100	2,400	200
Equity Securities, FV-NI, Unrealized Gain	16,800		8,900
Entergy Louisiana [Member]
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	$ 519,300		$ 519,300		490,000
Average coupon rate of debt securities	3.79%		3.79%
Average duration of debt securities, years			5 years 314 days
Average maturity of debt securities, years			11 years 234 days
Proceeds from the dispositions of debt securities	$ 43,900	85,000	$ 169,400	125,600
Gains from dispositions of debt securities, gross	10	5,000	500	5,000
Losses from dispositions of debt securities, gross	400	100	$ 1,200	300
Percentage Interest in River Bend			30.00%
Equity Securities, FV-NI, Unrealized Gain	22,200		$ 11,500
System Energy [Member]
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	$ 328,300		$ 328,300		327,500
Average coupon rate of debt securities	2.93%		2.93%
Average duration of debt securities, years			6 years 80 days
Average maturity of debt securities, years			9 years 44 days
Proceeds from the dispositions of debt securities	$ 145,200	177,700	$ 199,400	253,500
Gains from dispositions of debt securities, gross	200	400	300	500
Losses from dispositions of debt securities, gross	3,900	$ 600	4,500	$ 1,300
Equity Securities, FV-NI, Unrealized Gain	16,300		8,500
Indian Point 3 [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments, Fair Value	801,000		801,000		798,000
Indian Point 1 [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments, Fair Value	491,000		491,000		491,000
Indian Point 2 [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments, Fair Value	621,000		621,000		621,000
Palisades [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments, Fair Value	460,000		460,000		458,000
Pilgrim [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments, Fair Value	1,055,000		1,055,000		1,068,000
Vermont Yankee [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments, Fair Value	$ 585,000		$ 585,000		$ 613,000