Condensed Consolidated Statements of Operations (Unaudited) (USD $)
In Thousands, except Share data
 3 Months Ended 6 Months Ended
Jun. 30, 2011
Jun. 30, 2010
Jun. 30, 2011
Jun. 30, 2010
Revenues:        
Rental and other property income $ 62,853 $ 60,010 $ 123,836 $ 118,953
Tenant reimbursement income 3,906 3,551 8,693 7,126
Earned income from direct financing leases 485 497 971 1,071
Interest income on mortgage notes receivable 1,611 1,671 3,232 3,347
Interest income on marketable securities 521 1,907 2,459 3,793
Total revenue 69,376 67,636 139,191 134,290
Expenses:        
General and administrative expenses 1,941 1,840 3,943 3,893
Property operating expenses 5,655 5,169 11,467 10,264
Property and asset management expenses 4,106 4,065 8,462 8,377
Acquisition related expenses 1,956 625 2,318 625
Depreciation 14,912 14,018 29,569 28,044
Amortization 7,077 8,043 14,474 15,056
Impairment of real estate assets 0 4,500 0 4,500
Total operating expenses 35,647 38,260 70,233 70,759
Operating income 33,729 29,376 68,958 63,531
Other income (expense):        
Equity in income (loss) of unconsolidated joint ventures and other income 368 (10) 536 86
Gain on sale of marketable securities 7,728 0 15,587 0
Interest expense (26,898) (25,626) (53,419) (50,850)
Total other expense (18,802) (25,636) (37,296) (50,764)
Net income $ 14,927 $ 3,740 $ 31,662 $ 12,767
Weighted average number of common shares outstanding:        
Basic 209,586,828 206,653,839 209,430,055 205,989,957
Diluted 209,586,828 206,656,925 209,430,055 205,993,403
Net income per common share:        
Basic and diluted $ 0.07 $ 0.02 $ 0.15 $ 0.06
Distributions declared per common share $ 0.16 $ 0.16 $ 0.31 $ 0.31