Annual report pursuant to Section 13 and 15(d)

Commitment and Contingencies - Future Minimum Rental Payments Due under Terms of Leases (Detail)

v2.4.0.8
Commitment and Contingencies - Future Minimum Rental Payments Due under Terms of Leases (Detail) (USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Dec. 31, 2013
Operating Leased Assets [Line Items]  
For the year ended December 31, 2014 $ 62,160
For the year ended December 31, 2015 59,885
For the year ended December 31, 2016 56,004
For the year ended December 31, 2017 54,332
For the year ended December 31, 2018 52,527
Ground Leases [Member]
  
Operating Leased Assets [Line Items]  
For the year ended December 31, 2014 413
For the year ended December 31, 2015 413
For the year ended December 31, 2016 413
For the year ended December 31, 2017 416
For the year ended December 31, 2018 417
For the year ended December 31, 2019 417
Thereafter 4,503
Ground Leases [Member] | Tulsa, OK [Member]
  
Operating Leased Assets [Line Items]  
Lease End Date 2021-04
For the year ended December 31, 2014 153
For the year ended December 31, 2015 153
For the year ended December 31, 2016 153
For the year ended December 31, 2017 153
For the year ended December 31, 2018 153
For the year ended December 31, 2019 153
Thereafter 229
Ground Leases [Member] | Dartmouth, MA [Member]
  
Operating Leased Assets [Line Items]  
Lease End Date 2036-05
For the year ended December 31, 2014 174
For the year ended December 31, 2015 174
For the year ended December 31, 2016 174
For the year ended December 31, 2017 174
For the year ended December 31, 2018 174
For the year ended December 31, 2019 174
Thereafter 3,300
Ground Leases [Member] | Springfield, MA [Member]
  
Operating Leased Assets [Line Items]  
Lease End Date 2030-02
For the year ended December 31, 2014 86
For the year ended December 31, 2015 86
For the year ended December 31, 2016 86
For the year ended December 31, 2017 89
For the year ended December 31, 2018 90
For the year ended December 31, 2019 90
Thereafter $ 974