Investment in Office Properties - Purchase Price Allocation for Deerwood and Lincoln Place (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013
Business Acquisition [Line Items]
Land	$ 43,600
Buildings	580,616
Below market leases	(18,979)
Mortgage debt assumed	(58,694)
Tower Place 200, Deerwood North and South, Lincoln Place [Member]
Business Acquisition [Line Items]
Land	39,155
Buildings	170,549
Tenant Improvements	18,422
Leasing Commissions	9,123
In place leases	20,495
Above market leases	4,969
Below market leases	(9,267)
Mortgage premium assumed	2,804
Mortgage debt assumed	$ (49,369)