Consolidated Statement of Changes in Equity (USD $) In Thousands, except Share data	Total	Common Stock	Additional Capital	Retained Earnings	Treasury Stock	Alexander's Equity	Non-controlling Interest
Balance, at Dec. 31, 2010	$ 343,776	$ 5,173	$ 31,501	$ 304,055	$ (375)	$ 340,354	$ 3,422
Shares Issued, Beginning Balance at Dec. 31, 2010		5,173,000
Net income	17,812			18,207		18,207	(395)
Dividends paid	(15,318)			(15,318)		(15,318)
Balance, at Mar. 31, 2011	346,270	5,173	31,501	306,944	(375)	343,243	3,027
Shares Issued, Ending Balance at Mar. 31, 2011		5,173,000
Balance, at Dec. 31, 2011	363,245	5,173	31,801	322,201	(375)	358,800	4,445
Shares Issued, Beginning Balance at Dec. 31, 2011	5,173,450	5,173,000
Net income	19,424			19,482		19,482	(58)
Dividends paid	(19,151)			(19,151)		(19,151)
Balance, at Mar. 31, 2012	$ 363,518	$ 5,173	$ 31,801	$ 322,532	$ (375)	$ 359,131	$ 4,387
Shares Issued, Ending Balance at Mar. 31, 2012	5,173,450	5,173,000