Organization, Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Rent Collections (Details) - COVID-19	Dec. 31, 2020	Sep. 30, 2020
Core Portfolio | Second Quarter 2020
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Percentage of rent collections	76.00%	74.00%
Core Portfolio | Third Quarter 2020
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Percentage of rent collections	87.00%	85.00%
Core Portfolio | Fourth Quarter 2020
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Percentage of rent collections	91.00%
Opportunity Funds | Second Quarter 2020
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Percentage of rent collections	67.00%	65.00%
Opportunity Funds | Third Quarter 2020
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Percentage of rent collections	79.00%	77.00%
Opportunity Funds | Fourth Quarter 2020
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Percentage of rent collections	82.00%