Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Office rental
Rental revenues	$ 98,428	$ 97,740	$ 294,989	$ 295,059
Tenant recoveries	11,337	11,601	33,099	33,670
Parking and other income	17,658	17,100	52,800	51,006
Total office revenues	127,423	126,441	380,888	379,735
Multifamily rental
Rental revenues	17,157	16,372	50,844	48,647
Parking and other income	1,413	1,246	4,117	3,676
Total multifamily revenues	18,570	17,618	54,961	52,323
Total revenues	145,993	144,059	435,849	432,058
Operating Expenses
Office expense	44,293	44,294	127,684	127,081
Multifamily expense	4,999	4,832	14,860	14,317
General and administrative	6,610	6,954	20,051	21,260
Depreciation and amortization	46,546	45,872	139,071	160,139
Total operating expenses	102,448	101,952	301,666	322,797
Operating income	43,545	42,107	134,183	109,261
Other income	190	299	582	898
Loss including depreciation, from unconsolidated real estate funds	(663)	(285)	(2,764)	(2,064)
Interest expense	(36,844)	(37,717)	(110,996)	(110,245)
Net income (loss)	6,228	4,404	21,005	(2,150)
Less: Net (income) loss attributable to noncontrolling interests	(1,173)	(1,007)	(4,037)	182
Net income (loss) attributable to common stockholders	$ 5,055	$ 3,397	$ 16,968	$ (1,968)
Net income (loss) attributable to common stockholders per share - basic	$ 0.04	$ 0.03	$ 0.12	$ (0.02)
Net income (loss) attributable to common stockholders per share - diluted	$ 0.04	$ 0.03	$ 0.12	$ (0.02)
Dividends declared per common share	$ 0.15	$ 0.13	$ 0.45	$ 0.36