Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $)
In Thousands, except Share data
Jun. 30, 2011
Dec. 31, 2010
Investment in real estate assets:    
Accumulated depreciation on buildings and improvements $ 208,475 $ 178,906
Unearned income on real estate assets under direct financing leases 14,313 15,284
Accumulated amortization on acquired intangible lease assets 112,496 97,387
Allowance for doubtful accounts on rents and tenant receivables 460 646
Accumulated amortization on deferred financing costs 15,986 13,599
LIABILITIES AND STOCKHOLDERS' EQUITY    
Accumulated amortization on acquired below market lease intangibles $ 37,396 $ 32,095
STOCKHOLDERS' EQUITY:    
Preferred stock, par value $ 0.01 $ 0.01
Preferred stock, shares authorized 10,000,000 10,000,000
Preferred stock, shares issued 0 0
Preferred stock, shares outstanding 0 0
Common stock, par value $ 0.01 $ 0.01
Common stock, shares authorized 240,000,000 240,000,000
Common stock, shares issued 209,970,522 209,317,346
Common stock, shares outstanding 209,970,522 209,317,346