Consolidated Statements of Income (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
REVENUES
Property rentals	$ 43,829	$ 43,465
Expense reimbursements	19,831	19,407
Total revenues	63,660	62,872
EXPENSES
Operating (including fees to Vornado of $1,477 and $1,336, respectively)	21,262	21,187
Depreciation and amortization	8,697	8,234
General and administrative (including management fees to Vornado of $540 in each period)	1,124	1,099
Total expenses	31,083	30,520
OPERATING INCOME	32,577	32,352
Interest and other income, net	34	105
Interest and debt expense	(13,068)	(14,805)
Income before income taxes	19,543	17,652
Income tax (expense) benefit	(119)	160
Net income	19,424	17,812
Net loss attributable to the noncontrolling interest	58	395
Net income attributable to Alexander's	$ 19,482	$ 18,207
Net income per common share - basic
Net income per common share - basic	$ 3.81	$ 3.57
Weighted average shares outstanding - basic	5,106,984	5,105,936
Net income per common share - diluted
Net income per common share - diluted	$ 3.81	$ 3.57
Weighted average shares outstanding - diluted	5,106,984	5,105,936
Dividends per common share	$ 3.75	$ 3.00