Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended			3 Months Ended		9 Months Ended
	Oct. 31, 2021	Aug. 31, 2021	Jun. 30, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	May 01, 2021	Apr. 30, 2021	Dec. 31, 2020
Equity [Abstract]
Stock Options Excluded From Diluted Common Shares Outstanding Calculation				1,000,000	500,000	1,000,000	500,000
Common stock dividend (in dollars per share)				$ 0.95	$ 0.93	$ 2.85	$ 2.79
Shares Issued, Price Per Share		$ 111.16	$ 106.87
Equity Distribution Sales Agreement, Maximum Aggregate Gross Sales Price [Abstract]				$ 1,000.0		$ 1,000.0
Forward Sale Agreement, Aggregate Compensation to Sales Agents [Abstract]
Common Stock, Shares Authorized				499,000,000		499,000,000		499,000,000	500,000,000	500,000,000
Preferred Stock, Shares Authorized				1,000,000		1,000,000		1,000,000		0
Equity Distribution Sales Agreement, Net Sales Price						$ 26.8
Equity Distribution Sales Agreement, Gross Sales Price						28.2
Equity Distribution Sales Agreement, Aggregate Compensation to Sales Agents						0.3
Equity Distribution Sales Agreement, General Issuance Costs						$ 1.1
Forward Sale Agreement, Equity Offering Shares		1,692,555	416,853
Forward Sale Agreement, Gross Sales Price		$ 190.1	$ 45.0
Forward Sale Agreement, Aggregate Compensation to Sales Agents		$ 1.9	$ 0.5
Stock Issued During Period, Shares, Treasury Stock Reissued						465,135
Stock Issued During Period, Shares, New Issues				0		265,468
System Energy [Member]
Forward Sale Agreement, Aggregate Compensation to Sales Agents [Abstract]
Common Stock, Shares Authorized				1,000,000		1,000,000				1,000,000
Entergy Texas [Member]
Forward Sale Agreement, Aggregate Compensation to Sales Agents [Abstract]
Common Stock, Shares Authorized				200,000,000		200,000,000				200,000,000
Subsequent Event [Member]
Equity [Abstract]
Common stock dividend (in dollars per share)	$ 1.01
Shares Issued, Price Per Share	$ 100.35
Forward Sale Agreement, Aggregate Compensation to Sales Agents [Abstract]
Forward Sale Agreement, Equity Offering Shares	250,743
Forward Sale Agreement, Gross Sales Price	$ 25.4
Forward Sale Agreement, Aggregate Compensation to Sales Agents	$ 0.3