Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Additional Information (Details)

v3.20.4
Summary of Significant Accounting Policies - Additional Information (Details)
12 Months Ended
Sep. 22, 2020
$ / shares
shares
Dec. 31, 2020
USD ($)
asset_class
$ / shares
Dec. 31, 2019
USD ($)
$ / shares
Apr. 30, 2020
USD ($)
Jan. 01, 2019
USD ($)
Property, Plant and Equipment [Line Items]          
Asset retirement obligation   $ 0 $ 0    
Maturity of highly liquid investments   90 days      
Insurance coverage provided to a depositor's other deposit accounts held at an FDIC-insured institution   $ 250,000      
Past due rent charge term   5 days      
Allowance for uncollectible accounts   $ 994,000 1,140,000    
Tenant recoveries realized from previous charge-offs   $ 0 0    
Property management fee percentage   3.00%      
Asset management fee percentage   2.00%      
Minimum percentage of taxable income to be distributed to stockholders   90.00%      
Term of disqualification to be taxed as a REIT due to loss of REIT status   5 years      
Advertising costs for leasing activities   $ 117,000 $ 276,000    
Common stock, par value (in dollars per share) | $ / shares   $ 0.01 $ 0.01    
Operating lease right-of-use assets   $ 12,745,000 $ 11,651,000   $ 11,900,000
Operating lease liabilities   $ 13,200,000 $ 11,921,000   $ 11,990,000
Lease incremental borrowing rate         4.84%
Stock Repurchased and Retired During Period, Shares | shares 71,343        
Stock Repurchased And Retired, Price Per Share | $ / shares $ 15.50        
Lessor, Operating Lease, Number Of Underlying Asset Classes | asset_class   2      
Legal Fees   $ 1,040,000.00      
New Lease          
Property, Plant and Equipment [Line Items]          
Commission fee percentage for new leases   6.00% 3.00%    
KeyBank          
Property, Plant and Equipment [Line Items]          
Unsecured Debt       $ 552,000  
Debt interest rate       1.00%  
Buildings and improvements | Minimum          
Property, Plant and Equipment [Line Items]          
Estimated useful life of buildings and improvements   5 years      
Buildings and improvements | Maximum          
Property, Plant and Equipment [Line Items]          
Estimated useful life of buildings and improvements   40 years      
Rent and other tenant receivables          
Property, Plant and Equipment [Line Items]          
Unbilled rent asset, net   $ 4,480,000 $ 3,410,000