Long-Term Lease Obligations - Future Minimum Rental Commitments Under Ground Leases (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013
Leases Future Minimum Payments [Line Items]
2014	$ 176
2015	176
2016	176
2017	176
2018	176
Thereafter	9,363
Total	10,243
Beacon Center
Leases Future Minimum Payments [Line Items]
2014	60
2015	60
2016	60
2017	60
2018	60
Thereafter	2,601
Total	2,901
Olney
Leases Future Minimum Payments [Line Items]
2014	56
2015	56
2016	56
2017	56
2018	56
Thereafter	3,817
Total	4,097
Southdale
Leases Future Minimum Payments [Line Items]
2014	60
2015	60
2016	60
2017	60
2018	60
Thereafter	2,945
Total	$ 3,245