Schedule III - Real Estate and Accumulated Depreciation (Schedule of Real Estate Assets) (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances $ 559,393    
Initial Cost to Company, Land 494,670    
Initial Cost to Company, Building and Improvements 193,232    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 494,670    
Gross Amount Carried at Close of Period, Building and Improvements 193,232    
Gross Amount Carried at Close of Period, Total 687,902 $ 669,923 $ 413,145
Accumulated Depreciation 16,286 $ 10,257 $ 4,253
Aggregate cost for federal income tax purposes $ 963,100    
Minimum      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Depreciable Life (Years) 7 years    
Maximum      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Depreciable Life (Years) 12 years    
Detroit, MI      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances $ 31,961    
Initial Cost to Company, Land 29,086    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 29,086    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 29,086    
Accumulated Depreciation 0    
Dallas, TX      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 3,736    
Initial Cost to Company, Land 1,954    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 1,954    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 1,954    
Accumulated Depreciation 0    
Dallas, Texas      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 4,151    
Initial Cost to Company, Land 2,751    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 2,751    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 2,751    
Accumulated Depreciation 0    
Atlanta, GA      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 7,577    
Initial Cost to Company, Land 4,097    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 4,097    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 4,097    
Accumulated Depreciation 0    
DISTRICT OF COLUMBIA 2      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 23,100    
Initial Cost to Company, Land 27,354    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 27,354    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 27,354    
Accumulated Depreciation 0    
Milwaukee, WI      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 3,633    
Initial Cost to Company, Land 4,638    
Initial Cost to Company, Building and Improvements 51,323    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 4,638    
Gross Amount Carried at Close of Period, Building and Improvements 51,323    
Gross Amount Carried at Close of Period, Total 55,961    
Accumulated Depreciation $ 3,500    
Depreciable Life (Years) 40 years    
Washington, DC      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances $ 5,190    
Initial Cost to Company, Land 1,484    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 1,484    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 1,484    
Accumulated Depreciation 0    
Minneapolis, MN      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 1,452    
Initial Cost to Company, Land 716    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 716    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 716    
Accumulated Depreciation 0    
Durango, CO      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 16,604    
Initial Cost to Company, Land 1,415    
Initial Cost to Company, Building and Improvements 17,080    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 1,415    
Gross Amount Carried at Close of Period, Building and Improvements 17,080    
Gross Amount Carried at Close of Period, Total 18,495    
Accumulated Depreciation $ 1,480    
Depreciable Life (Years) 35 years    
Rohnert Park, CA      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances $ 19,300    
Initial Cost to Company, Land 5,869    
Initial Cost to Company, Building and Improvements 13,752    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 5,869    
Gross Amount Carried at Close of Period, Building and Improvements 13,752    
Gross Amount Carried at Close of Period, Total 19,621    
Accumulated Depreciation $ 1,480    
Depreciable Life (Years) 32 years    
Salt Lake City, UT      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances $ 55,312    
Initial Cost to Company, Land 8,573    
Initial Cost to Company, Building and Improvements 40,583    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 8,573    
Gross Amount Carried at Close of Period, Building and Improvements 40,583    
Gross Amount Carried at Close of Period, Total 49,156    
Accumulated Depreciation $ 3,240    
Depreciable Life (Years) 34 years    
San Diego, CA      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances $ 38,084    
Initial Cost to Company, Land 5,077    
Initial Cost to Company, Building and Improvements 24,096    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 5,077    
Gross Amount Carried at Close of Period, Building and Improvements 24,096    
Gross Amount Carried at Close of Period, Total 29,173    
Accumulated Depreciation $ 2,032    
Depreciable Life (Years) 33 years    
DISTRICT OF COLUMBIA 3      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances $ 10,000    
Initial Cost to Company, Land 15,217    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 15,217    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 15,217    
Accumulated Depreciation 0    
Seattle, WA      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 40,000    
Initial Cost to Company, Land 7,813    
Initial Cost to Company, Building and Improvements 45,562    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 7,813    
Gross Amount Carried at Close of Period, Building and Improvements 45,562    
Gross Amount Carried at Close of Period, Total 53,375    
Accumulated Depreciation $ 4,530    
Depreciable Life (Years) 30 years    
Los Angeles, CA      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances $ 57,936    
Initial Cost to Company, Land 68,140    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 68,140    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 68,140    
Accumulated Depreciation 0    
Los Angeles, CA 2      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 62,764    
Initial Cost to Company, Land 72,836    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 72,836    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 72,836    
Accumulated Depreciation 0    
Atlanta, GA 2      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 0    
Initial Cost to Company, Land 6,300    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 6,300    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 6,300    
Accumulated Depreciation 0    
Orlando, FL      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 7,800    
Initial Cost to Company, Land 6,626    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 6,626    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 6,626    
Accumulated Depreciation 0    
Atlanta, GA 3      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 18,000    
Initial Cost to Company, Land 11,449    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 11,449    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 11,449    
Accumulated Depreciation 0    
Raleigh-Durham, NC      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 11,940    
Initial Cost to Company, Land 4,502    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 4,502    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 4,502    
Accumulated Depreciation 0    
Atlanta, GA 4      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 9,882    
Initial Cost to Company, Land 8,478    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 8,478    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 8,478    
Accumulated Depreciation 0    
San Diego, CA 2      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 0    
Initial Cost to Company, Land 8,168    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 8,168    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 8,168    
Accumulated Depreciation 0    
Phoenix, AZ      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 0    
Initial Cost to Company, Land 5,996    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 5,996    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 5,996    
Accumulated Depreciation 0    
DISTRICT OF COLUMBIA 4      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 0    
Initial Cost to Company, Land 21,478    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 21,478    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 21,478    
Accumulated Depreciation 0    
Miami, FL      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 6,000    
Initial Cost to Company, Land 3,735    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 3,735    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 3,735    
Accumulated Depreciation 0    
Miami, FL 2      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 2,471    
Initial Cost to Company, Land 9,170    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 9,170    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 9,170    
Accumulated Depreciation 0    
DISTRICT OF COLUMBIA 5      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 95,000    
Initial Cost to Company, Land 121,100    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 121,100    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 121,100    
Accumulated Depreciation 0    
Nashville, TN      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 17,500    
Initial Cost to Company, Land 13,505    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 13,505    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 13,505    
Accumulated Depreciation 0    
Portland, OR      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 0    
Initial Cost to Company, Land 3,641    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 3,641    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 3,641    
Accumulated Depreciation 0    
San Antonio, TX      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances 10,000    
Initial Cost to Company, Land 2,103    
Initial Cost to Company, Building and Improvements 836    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 2,103    
Gross Amount Carried at Close of Period, Building and Improvements 836    
Gross Amount Carried at Close of Period, Total 2,939    
Accumulated Depreciation $ 24    
Depreciable Life (Years) 40 years    
Riverside, CA      
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items]      
Encumbrances $ 0    
Initial Cost to Company, Land 11,399    
Initial Cost to Company, Building and Improvements 0    
Cost Capitalized Subsequent to Acquisition 0    
Gross Amount Carried at Close of Period, Land 11,399    
Gross Amount Carried at Close of Period, Building and Improvements 0    
Gross Amount Carried at Close of Period, Total 11,399    
Accumulated Depreciation $ 0