Intangibles - Summary of Carrying Amount of Intangible Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Assets
Cost	$ 513,434	$ 452,384
Accumulated Amortization	(135,782)	(127,557)
Net	377,652	324,827
Liabilities
Below market lease, net	7,336	13,585
Lease liability, cost	61,043	0
Lease liability, accumulated amortization	(179)	0
Lease liability	60,864	0
Cost	75,544	20,619
Accumulated Amortization	(7,344)	(7,034)
Net	68,200	13,585
In-place lease intangibles
Assets
Cost	340,478	340,428
Accumulated Amortization	(120,364)	(111,500)
Net	220,114	228,928
Above-market leases
Assets
Cost	45,517	45,568
Accumulated Amortization	(14,684)	(13,621)
Net	30,833	31,947
Leasehold interest
Assets
Cost	712	712
Accumulated Amortization	(257)	(242)
Net	455	470
Below-market ground leases
Assets
Cost	0	65,676
Accumulated Amortization	0	(2,194)
Net	0	63,482
Right-of-use lease asset
Assets
Cost	126,727	0
Accumulated Amortization	(477)	0
Net	126,250	0
Below-market leases
Liabilities
Below market lease, cost	14,501	14,654
Below market lease, accumulated amortization	(7,165)	(6,768)
Below market lease, net	7,336	7,886
Above-market ground leases
Liabilities
Below market lease, cost	0	5,965
Below market lease, accumulated amortization	0	(266)
Below market lease, net	$ 0	$ 5,699