Decommissioning Trust Funds (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Jan. 01, 2019
Debt Securities, Trading, Measurement Input	$ 538,000		$ 538,000		$ 507,000
Decommissioning Trust Funds [Abstract]
Accumulated Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, after Tax						$ (6,806)
Deferred taxes on unrealized gains/(losses) recorded in OCI for non-regulated decommissioning trusts	10,812	$ 8,096	19,555	$ 16,169
Amortized cost of debt securities	$ 2,381,000		$ 2,381,000		2,366,000
Average coupon rate of debt securities	3.19%		3.19%
Average duration of debt securities, years			7 years 29 days
Average maturity of debt securities, years			10 years 5 months 12 days
Proceeds from the dispositions of debt securities	$ 276,000	361,000	$ 676,000	726,000
Gains from dispositions of debt securities, gross	15,000	6,000	29,000	8,000
Losses from dispositions of debt securities, gross	1,000	1,000	4,000	3,000
Equity Securities, FV-NI, Unrealized Loss			126,000
Debt Securities, Available-for-sale, Allowance for Credit Loss	400		400
Equity Securities, FV-NI, Unrealized Gain	508,000
Debt Securities [Member]
Decommissioning Trust Funds [Abstract]
Deferred taxes on unrealized gains/(losses) recorded in OCI for non-regulated decommissioning trusts			33,000		13,000
Entergy Arkansas [Member]
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	$ 411,600		$ 411,600		405,400
Average coupon rate of debt securities	2.72%		2.72%
Average duration of debt securities, years			7 years 2 months 4 days
Average maturity of debt securities, years			8 years 7 months 13 days
Proceeds from the dispositions of debt securities	$ 17,700	22,300	$ 66,400	33,200
Gains from dispositions of debt securities, gross	1,300	100	5,800	100
Losses from dispositions of debt securities, gross	100	18	200	100
Equity Securities, FV-NI, Unrealized Loss			30,400
Equity Securities, FV-NI, Unrealized Gain	116,800
Entergy Louisiana [Member]
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	$ 573,300		$ 573,300		573,000
Average coupon rate of debt securities	3.84%		3.84%
Average duration of debt securities, years			7 years 2 months 15 days
Average maturity of debt securities, years			12 years 11 months 15 days
Proceeds from the dispositions of debt securities	$ 34,100	39,500	$ 101,500	95,700
Gains from dispositions of debt securities, gross	2,000	1,400	4,900	1,700
Losses from dispositions of debt securities, gross	100	50	$ 700	200
Percentage Interest in River Bend			30.00%
Equity Securities, FV-NI, Unrealized Loss			$ 40,100
Equity Securities, FV-NI, Unrealized Gain	160,800
System Energy [Member]
Decommissioning Trust Funds [Abstract]
Amortized cost of debt securities	$ 386,700		$ 386,700		371,400
Average coupon rate of debt securities	2.97%		2.97%
Average duration of debt securities, years			7 years 4 months 20 days
Average maturity of debt securities, years			11 years 2 months 8 days
Proceeds from the dispositions of debt securities	$ 73,600	87,700	$ 165,600	129,800
Gains from dispositions of debt securities, gross	5,400	1,500	7,000	1,900
Losses from dispositions of debt securities, gross	200	$ 300	400	$ 400
Equity Securities, FV-NI, Unrealized Loss			28,900
Equity Securities, FV-NI, Unrealized Gain	111,100
Indian Point 3 [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments, Fair Value	945,000		945,000		930,000
Indian Point 1 [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments, Fair Value	565,000		565,000		556,000
Indian Point 2 [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments, Fair Value	715,000		715,000		701,000
Palisades [Member]
Decommissioning Trust Funds [Abstract]
Decommissioning Fund Investments, Fair Value	$ 528,000		$ 528,000		$ 498,000