Statements of Changes in Common Equity (ENTERGY MISSISSIPPI, INC.) (Unaudited) (USD $) In Thousands	Total		Common Stock	Retained Earnings		Entergy Mississippi	Entergy Mississippi Common Stock	Entergy Mississippi Capital Stock Expense and Other [Member]	Entergy Mississippi Retained Earnings
Beginning Balance at Dec. 31, 2009	$ 8,707,360		$ 2,548	$ 8,043,122		$ 688,765	$ 199,326	$ (690)	$ 490,129
Net income	1,036,999	[1]		1,021,951	[1]	79,476			79,476
Common stock	(453,683)					(43,400)			(43,400)
Preferred stock	(15,048)					(2,121)			(2,121)
Ending Balance at Sep. 30, 2010	8,825,752		2,548	8,611,081		722,720	199,326	(690)	524,084
Beginning Balance at Jun. 30, 2010
Net income	497,901					34,014
Ending Balance at Sep. 30, 2010	8,825,752		2,548			722,720	199,326	(690)
Beginning Balance at Dec. 31, 2010	8,590,400		2,548	8,689,401		726,224	199,326	(690)	527,588
Net income	1,207,346	[1]		1,192,300	[1]	74,211			74,211
Common stock	(443,290)					(3,300)			(3,300)
Preferred stock	(15,046)					(2,121)			(2,121)
Ending Balance at Sep. 30, 2011	9,059,362		2,548	9,439,000		795,014	199,326	(690)	596,378
Beginning Balance at Jun. 30, 2011
Net income	633,069					33,069
Ending Balance at Sep. 30, 2011	$ 9,059,362		$ 2,548			$ 795,014	$ 199,326	$ (690)

[1] Consolidated net income and preferred dividend requirements of subsidiaries for both 2010 and 2011 include $10.1 million of preferred dividends on subsidiaries' preferred stock without sinking fund that is not presented as equity.