Future Minimum Rent (Schedule of Future Minimum Rental Payments Under Non-Cancelable Ground Leases) (Details) $ in Thousands |
Mar. 31, 2019
lease
|
Dec. 31, 2018
USD ($)
lease
|
|---|---|---|
| Leases [Abstract] | ||
| Number of operating ground leases | lease | 6 | 3 |
| Number of ground leases paid directly by the tenant | lease | 1 | |
| 2019 | $ 123 | |
| 2020 | 123 | |
| 2021 | 123 | |
| 2022 | 123 | |
| 2023 | 123 | |
| Thereafter | 2,246 | |
| Total | $ 2,861 |