Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 8,339	$ 10,833
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of building and improvements and leasing costs	61,029	44,229
Increase in provision for bad debts	146	14
Depreciation of furniture, fixtures and equipment	530	431
Noncash amortization of share-based compensation awards	2,239	3,519
Noncash amortization of deferred financing costs and debt discounts and premiums	6,884	5,750
Noncash amortization of above/(below) market rents (Note 3)	1,398	32
Loss on early extinguishment of debt		4,564
Noncash amortization of deferred revenue related to tenant-funded tenant improvements	(4,668)	(4,775)
Changes in operating assets and liabilities:
Marketable securities	(752)	(635)
Current receivables	1,380	483
Deferred rent receivables	(8,906)	(5,421)
Other deferred leasing costs	398	(2,594)
Prepaid expenses and other assets	(3,519)	(2,991)
Accounts payable, accrued expenses and other liabilities	(6,384)	(4,177)
Deferred revenue	(577)	507
Rents received in advance and tenant security deposits	(1,072)	7,619
Net cash provided by operating activities	56,465	57,388
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for acquisition of operating properties (Note 2)	(378,554)	(373,574)
Expenditures for operating properties	(28,230)	(33,593)
Expenditures for development and redevelopment properties and undeveloped land	(12,347)	(8,113)
Net increase in escrow deposits	(16,500)
Decrease in restricted cash	112	1,096
Receipt of principal payments on note receivable		76
Net cash used in investing activities	(435,519)	(414,108)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from issuance of common stock (Note 7)	221,015	299,847
Borrowings on unsecured line of credit	302,000	288,000
Repayments on unsecured line of credit	(216,000)	(235,000)
Principal payments on secured debt	(3,403)	(100,104)
Repurchase of exchangeable senior notes		(151,097)
Proceeds from issuance of secured debt (Note 5)	135,000	71,000
Proceeds from issuance of unsecured debt		247,870
Financing costs	(5,201)	(4,643)
Decrease in loan deposits	2,027	1,420
Repurchase of common stock and restricted stock units	(732)	(2,121)
Proceeds from exercise of stock options	395	83
Dividends and distributions paid to common stockholders and common unitholders	(37,877)	(31,392)
Dividends and distributions paid to preferred stockholders and preferred unitholders	(7,598)	(7,598)
Net cash provided by financing activities	389,626	376,265
Net increase in cash and cash equivalents	10,572	19,545
Cash and cash equivalents, beginning of period	14,840	9,883
Cash and cash equivalents, end of period	25,412	29,428
SUPPLEMENTAL CASH FLOWS INFORMATION:
Cash paid for interest, net of capitalized interest of $3,327 and $4,055 as of June 30, 2011 and 2010, respectively	34,568	18,634
NONCASH INVESTING TRANSACTIONS:
Accrual for expenditures for operating properties and development and redevelopment properties	9,966	11,378
Tenant improvements funded directly by tenants to third parties	3,027	1,946
Assumption of secured debt with property acquisition (Notes 2 and 5)	30,042	51,079
Assumption of other liabilities with property acquisitions (Note 2)	4,438	6,369
NONCASH FINANCING TRANSACTIONS:
Accrual of dividends and distributions payable to common stockholders and common unitholders	21,064	18,907
Accrual of dividends and distributions payable to preferred stockholders and preferred unitholders	1,909	1,909
Issuance of share-based compensation awards (Note 9)	7,216	5,418
Exchange of common units of the Operating Partnership into shares of the Company's common stock	$ 91