Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 1,674	$ 1,674
Total intangible assets	283,139	145,883
In-place Leases
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	229,100	105,964
Accumulated amortization	141,773	125,130
Above-market Tenant Leases
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	34,711	20,453
Accumulated amortization	22,378	19,502
Below-market Ground Lease
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	17,654	17,792
Accumulated amortization	$ 759	$ 621