Annual report pursuant to Section 13 and 15(d)

Commitments and Contingencies (Details)

v2.4.0.6
Commitments and Contingencies (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Future minimum rental payments due      
2013 $ 50,534    
2014 49,719    
2015 46,431    
2016 42,240    
2017 40,239    
Thereafter 266,545    
Ground Leases [Member]
     
Future minimum rental payments due      
2013 413    
2014 413    
2015 413    
2016 413    
2017 416    
2018 417    
Thereafter 4,915    
Commitments and Contingencies (Textual) [Abstract]      
Expenses incurred for the properties listed 426 191 140
Ground Leases [Member] | Tulsa, OK [Member]
     
Future minimum rental payments due      
Lease End Date 2021-04    
2013 153    
2014 153    
2015 153    
2016 153    
2017 153    
2018 153    
Thereafter 381    
Ground Leases [Member] | Springfield, MA [Member]
     
Future minimum rental payments due      
Lease End Date 2030-02    
2013 86    
2014 86    
2015 86    
2016 86    
2017 89    
2018 90    
Thereafter 1,064    
Ground Leases [Member] | Dartmouth, MA [Member]
     
Future minimum rental payments due      
Lease End Date 2036-05    
2013 174    
2014 174    
2015 174    
2016 174    
2017 174    
2018 174    
Thereafter $ 3,470