Quarterly report pursuant to Section 13 or 15(d)

Discontinued Operations and Assets Held for Sale (Details)

v2.4.0.6
Discontinued Operations and Assets Held for Sale (Details) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 9 Months Ended 0 Months Ended
Sep. 30, 2012
Sep. 30, 2011
Sep. 30, 2012
Sep. 30, 2011
Dec. 31, 2011
Sep. 30, 2012
Assets Held-for-sale
Property
Dec. 31, 2011
Assets Held-for-sale
Dec. 15, 2011
Rutherford Business Center Portfolio
Property
Sep. 29, 2011
Towson Portfolio
Property
Jan. 30, 2012
White Marsh Portfolio Disposition Property
Property
Jul. 25, 2012
July 2012 Portfolio Disposition
Property
Discontinued Operations and Disposal Groups [Abstract]                      
Revenue from real estate operations $ 6,403 $ 17,151 $ 33,849 $ 51,363              
Property operating expenses (2,217) (6,325) (12,223) (19,684)              
Depreciation and amortization (1,926) (4,763) (8,457) (16,896)              
Impairment losses (9,733) 0 (23,510) (29,364)              
Business development and land carry costs 0 (17) (24) (56)              
Interest expense (127) (1,453) (2,107) (4,526)              
Gain on sales of real estate 16,913 1,299 20,948 1,438              
Gain (loss) on early extinguishment of debt 1,738 (384) 1,736 (384)              
Discontinued operations 11,051 5,508 10,212 (18,109)              
Properties                      
Number of properties sold               13 4 5 23
Number of operating properties classified as held for sale           16          
Properties, net 3,102,514   3,102,514   3,352,975 126,789 108,356        
Deferred rent receivable 83,156   83,156   86,856 3,733 2,800        
Intangible assets on real estate acquisitions, net 81,059   81,059   89,120 4,417 1,737        
Deferred leasing and financing costs, net           2,781 3,723        
Lease incentives 5,595   5,595   5,233 95 0        
Assets held for sale $ 137,815   $ 137,815   $ 116,616 $ 137,815 $ 116,616