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Real Estate and Intangible Assets - Leasing Activity (Details) $ in Thousands |  |  | 12 Months Ended |
--- | --- | --- | --- | ---
Dec. 01, 2017 ft² | May 31, 2016 property | Dec. 31, 2018 USD ($) ft² property | Dec. 31, 2017 USD ($) ft² property | Dec. 31, 2016 USD ($) | Jul. 25, 2014 ft²
Real Estate Properties [Line Items] |  |  |  |  |  |
Number of leased properties | property |  |  | 3 | 9 |  |
Aggregate Square Footage | ft² |  |  | 97,178 | 880,749 |  |
Annualized GAAP Rent |  |  | $ 1,253 | $ 6,976 |  |
Tenant Improvement |  |  | 433 | 1,264 |  |
Leasing Commissions |  |  | 242 | 742 |  |
Aggregate Deferred Rent Write Off |  |  | 200 | 0 | $ 0 |
Tenant reimbursements |  |  | 3,530 | 1,988 | 1,489 |
Property area | ft² |  |  |  |  |  | 81,371
Rental revenue |  |  | $ 103,268 | $ 92,811 | 84,498 |
Lease Contraction |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |
Number of leased properties | property |  |  | 2 | 0 |  |
Aggregate Square Footage | ft² |  |  | 169,133 |  |  |
Aggregate Square Footage Reduced | ft² |  |  | 44,032 |  |  |
Aggregate Deferred Rent Write Off |  |  | $ 184 |  |  |
Rental revenue |  |  | $ 559 |  |  |
Weighted Average |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |
Lease Term |  |  | 5 years 3 months 15 days | 9 years 2 months 12 days |  |
Minimum |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |
Lease Term |  |  | 3 years 7 months 6 days | 1 year |  |
Maximum |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |
Lease Term |  |  | 7 years | 11 years 3 months |  |
Newburyport, Massachusetts |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |
Number of leased properties | property |  | 1 |  |  |  |
Tenant reimbursements |  |  |  |  | 900 |
Other Income | Newburyport, Massachusetts |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |
Tenant reimbursements |  |  |  |  | 300 |
Vance, Alabama Industrial Building |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |
Property area | ft² |  |  |  | 75,000 |  |
Buildings and improvements, gross |  |  |  | $ 6,700 |  |
Rental revenue |  |  | $ 2,100 | $ 1,800 | $ 1,200 |
Vance, Alabama Industrial Building | Maximum |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |
Lease Term |  |  |  | 10 years |  |
Salt Lake City, Utah |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |
Lease Term | 10 years 1 month 6 days |  |  |  |  |
Property area | ft² | 102,028 |  |  |  |  |
Salt Lake City, Utah | Lease Contraction |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |
Aggregate Square Footage | ft² |  |  | 81,271 |  |  |
Aggregate Square Footage Reduced | ft² |  |  | 23,632 |  |  |
Aggregate Deferred Rent Write Off |  |  | $ 100 |  |  |
Rental revenue |  |  | $ 300 |  |  |
Champaign, Illinois | Lease Contraction |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |
Aggregate Square Footage | ft² |  |  | 87,862 |  |  |
Aggregate Square Footage Reduced | ft² |  |  | 20,400 |  |  |
Aggregate Deferred Rent Write Off |  |  | $ 100 |  |  |
Rental revenue |  |  | $ 200 |  |  |

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