Credit Risk Concentrations - Additional Information (Detail) - Customer |
3 Months Ended | 9 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|---|
Sep. 30, 2021 |
Sep. 30, 2020 |
Sep. 30, 2021 |
Sep. 30, 2020 |
Dec. 31, 2020 |
|
| Concentration Risk [Line Items] | |||||
| Number of tenants or common franchises | 0 | 0 | 0 | 0 | |
| Mortgages and Notes Payable | Credit Availability Concentration Risk | Financial Institution One | |||||
| Concentration Risk [Line Items] | |||||
| Concentrations risk percentage | 68.00% | 63.00% | |||
| Mortgages and Notes Payable | Credit Availability Concentration Risk | Financial Institution Two | |||||
| Concentration Risk [Line Items] | |||||
| Concentrations risk percentage | 18.00% | 16.00% | |||
| Mortgages and Notes Payable | Credit Availability Concentration Risk | Financial Institution Three | |||||
| Concentration Risk [Line Items] | |||||
| Concentrations risk percentage | 10.00% | ||||