Investments - Schedule of Lease Intangible Assets and Liabilities, Net of Accumulated Amortization (Details) - USD ($) $ in Thousands |
Mar. 31, 2019 |
Dec. 31, 2018 |
|---|---|---|
| Lessor, Lease, Description [Line Items] | ||
| Less: accumulated amortization | $ (148,201) | $ (149,582) |
| Intangible lease assets, net | 291,095 | 294,463 |
| In-place leases | ||
| Lessor, Lease, Description [Line Items] | ||
| Intangible lease assets, gross | 370,592 | 381,143 |
| Above-market leases | ||
| Lessor, Lease, Description [Line Items] | ||
| Intangible lease assets, gross | 68,704 | 62,902 |
| Below-market leases | ||
| Lessor, Lease, Description [Line Items] | ||
| Below-market leases | 158,594 | 167,527 |
| Less: accumulated amortization | (43,789) | (47,365) |
| Intangible lease liabilities, net | $ 114,805 | $ 120,162 |