Fair Value Measurements (Tables)
 12 Months Ended
Dec. 31, 2020
Fair Value Disclosures [Abstract]  
Fair Value Measurements, Nonrecurring The following table sets forth the Company’s assets that were accounted for at fair value on a nonrecurring basis as of their respective measurement dates (in thousands):
           
Fair Value Hierarchy Level
  
Description
   
    Fair Value    
     
    Level 1    
     
    Level 2    
     
    Level 3    
  
Assets held at December 31, 2020
                                    
Impaired at March 31, 2020
    $ 36,491       $             —       $             —       $         36,491   
Impaired at June 30, 2020
    $ 8,055       $ —       $ —       $ 8,055   
Impaired at September 30, 2020
    $ 10,027       $ —       $ —       $ 10,027   
Impaired at December 31, 2020
    $         14,259       $ —       $ —       $ 14,259   
Assets held at December 31, 2019
                                    
Impaired at June 30, 2019
    $ 1,893       $ —       $ —       $ 1,893   
Impaired at September 30, 2019
    $ 1,093       $ —       $ —       $ 1,093   
Impaired at December 31, 2019
    $ 11,594       $ —       $ —       $ 11,594   
Fair Value Inputs of Long-Lived Assets Held and Used and Held for Sale The unobservable inputs for the remaining properties are as follows:
Unobservable Input
  
 Asset Type 
    
 Property    
Count    
    
  Price Per Square Foot  
Range
    
    Weighted Average
Price
 
Per
Square Foot
    
Square

    Footage    
  
December 31, 2020
                                        
PSA, LOI or BOV
     Retail       11      
$16.67 - $338.98
       $43.32       577,945    
Comparable Properties
     Retail       10       $4.35 - $282.08       $57.62       431,563    
Comparable Properties
     Office       1      
$79.80 - $103.79
       $89.25       28,804    
           
December 31, 2019
                                        
PSA, LOI or BOV
     Retail       10      
$
24.78
 - $
323.00
       $50.71       165,773    
PSA, LOI or BOV
     Office       1       $
99.37
       $99.37       4,310    
Comparable Properties
     Retail       4      
$
34.45
 - $
740.74
       $104.84       35,885    
 
Schedule of Carrying Amount and Estimated Fair Value of Financial Instruments The following table discloses fair value information for these financial instruments (in thousands):
    
December 31, 2020
     
December 31, 2019
  
    
    Carrying    

Value
     
  Estimated  

Fair Value
     
    Carrying    

Value
     
  Estimated  

Fair Value
  
Loans receivable, net
    $ —        $ —        $ 34,465        $ 35,279    
2019 Credit Facility
      —          —          116,500          119,802    
2020 Term Loans, net 
(1)
      177,309          177,884          —          —    
Senior Unsecured Notes
, net
 
(1)
      1,927,348          2,122,409          1,484,066          1,543,919    
Mortgages and notes payable, net 
(1)
      212,582          226,240          216,049          235,253    
Convertible Notes, net 
(1)
      189,102          194,124          336,402          356,602    
 
(1)
 
The carrying value of the debt instruments are net of unamortized deferred financing costs and certain debt discounts/premiums.