Quarterly report pursuant to Section 13 or 15(d)

Properties, Net (Details 3)

v3.8.0.1
Properties, Net (Details 3)
$ in Thousands
Sep. 30, 2017
USD ($)
Property
Dec. 31, 2016
USD ($)
Property
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]    
Assets held for sale, net $ 74,415 $ 94,654
Assets held for sale, net    
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]    
Properties, net 68,081 85,402
Deferred rent receivable 5,582 4,241
Intangible assets on real estate acquisitions, net 0 338
Deferred leasing costs, net 742 3,636
Lease incentives, net 10 1,037
Assets held for sale, net $ 74,415 $ 94,654
Defense/Information Technology Locations | Data Center Shells | Assets held for sale, net    
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]    
Number of properties | Property 2  
Defense/Information Technology Locations | Northern Virginia Defense/IT | Assets held for sale, net    
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]    
Number of properties | Property   1
Defense/Information Technology Locations | Fort Meade/BW Corridor | Assets held for sale, net    
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]    
Number of properties | Property 1  
Regional Office and Other [Member] | White Marsh, Maryland | Assets held for sale, net    
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]    
Number of properties | Property   8