Investments - Schedule of Minimum Future Contractual Rent to be Received (Details) $ in Thousands |
Mar. 31, 2018
USD ($)
|
|---|---|
| Operating Leases, Future Contractual Rent Receivable | |
| Remainder of 2018 | $ 448,005 |
| 2019 | 587,122 |
| 2020 | 570,318 |
| 2021 | 542,008 |
| 2022 | 504,471 |
| Thereafter | 3,608,539 |
| Total future minimum rentals | $ 6,260,463 |