Quarterly report pursuant to Section 13 or 15(d)

Commitments and Contingencies (Details)

v2.4.0.6
Commitments and Contingencies (Details) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended
Mar. 31, 2013
Future minimum rental payments due under the terms of these leases  
2014 $ 50,811
2015 48,639
2016 45,121
2017 43,117
2018 41,007
Thereafter 236,596
Ground Leases [Member]
  
Future minimum rental payments due under the terms of these leases  
2014 311
2015 413
2016 413
2017 413
2018 416
2018 417
Thereafter 4,915
Ground Leases [Member] | Tulsa, OK [Member]
  
Future minimum rental payments due under the terms of these leases  
Lease End Date 2021-04
2014 115
2015 153
2016 153
2017 153
2018 153
2018 153
Thereafter 381
Ground Leases [Member] | Dartmouth, MA [Member]
  
Future minimum rental payments due under the terms of these leases  
Lease End Date 2036-05
2014 131
2015 174
2016 174
2017 174
2018 174
2018 174
Thereafter 3,470
Ground Leases [Member] | Springfield, MA [Member]
  
Future minimum rental payments due under the terms of these leases  
Lease End Date 2030-02
2014 65
2015 86
2016 86
2017 86
2018 89
2018 90
Thereafter $ 1,064