Condensed Consolidated Unaudited Balance Sheets (Parenthetical) (USD $)
In Thousands, except Share data, unless otherwise specified
Jun. 30, 2013
Dec. 31, 2012
Statement of Financial Position [Abstract]    
Accumulated depreciation on buildings and improvements $ 326,676 $ 297,422
Unearned income on real estate assets under direct financing leases 10,815 11,454
Accumulated amortization on acquired intangible lease assets 174,422 159,639
Allowance for doubtful accounts on rents and tenant receivables 72 80
Accumulated amortization on deferred financing costs 23,805 20,499
Accumulated amortization on acquired below market lease intangibles $ 56,049 $ 53,557
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 208,584,611 208,597,575
Common stock, shares outstanding 208,584,611 208,597,575