CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 41,896	$ 36,769
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation	26,016	23,897
Net amortization of debt premium and deferred financing fees	1,002	998
Straight line rental income	(2,308)	(2,669)
Amortization of acquired real estate leases	15,775	14,352
Amortization of deferred leasing costs	1,126	636
Other non-cash expenses	938	1,477
Loss on asset impairment	10,142
Net gain on sale of properties	(8,168)
Equity in earnings of an investee	(219)	(236)
Change in assets and liabilities:
Restricted cash	(37)	(453)
Deferred leasing costs	(3,118)	(2,123)
Rents receivable	(483)	4,863
Other assets	(2,780)	(1,077)
Accounts payable and accrued expenses	4,009	2,690
Due to related persons	(1,450)	3,336
Cash provided by operating activities	82,341	82,460
CASH FLOWS FROM INVESTING ACTIVITIES:
Real estate acquisitions and deposits	(35,848)	(180,976)
Real estate improvements	(14,924)	(10,474)
Proceeds from sale of properties, net	18,319
Cash used in investing activities	(32,453)	(191,450)
CASH FLOWS FROM FINANCING ACTIVITIES:
Repayment of mortgage notes payable	(1,434)	(1,327)
Borrowings on unsecured revolving credit facility	107,500	173,000
Repayments on unsecured revolving credit facility	(88,000)	(351,500)
Proceeds from unsecured term loan		350,000
Financing fees		(1,964)
Distributions to common shareholders	(70,512)	(59,322)
Cash provided by (used in) financing activities	(52,446)	108,887
Decrease in cash and cash equivalents	(2,558)	(103)
Cash and cash equivalents at beginning of period	5,255	3,272
Cash and cash equivalents at end of period	2,697	3,169
Supplemental cash flow information:
Interest paid	11,386	11,787
Income taxes paid	173	167
Non-cash financing activities:
Issuance of common shares	$ 1,694	$ 1,847