Intangibles - Carrying Amount of Intangible Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Cost	$ 452,384	$ 458,713
Accumulated Amortization	(127,557)	(98,919)
Net	324,827	359,794
Liability
Cost	20,619	20,309
Accumulated Amortization	(7,034)	(4,607)
Net	13,585	15,702
In-place leases
Finite-Lived Intangible Assets [Line Items]
Cost	340,428	343,429
Accumulated Amortization	(111,500)	(85,424)
Net	228,928	258,005
Above-market leases
Finite-Lived Intangible Assets [Line Items]
Cost	45,568	54,148
Accumulated Amortization	(13,621)	(11,968)
Net	31,947	42,180
Leasehold interest
Finite-Lived Intangible Assets [Line Items]
Cost	712	712
Accumulated Amortization	(242)	(183)
Net	470	529
Below-market ground lease
Finite-Lived Intangible Assets [Line Items]
Cost	65,676	60,424
Accumulated Amortization	(2,194)	(1,344)
Net	63,482	59,080
Below-market lease
Liability
Below market lease, cost	14,654	14,344
Below market lease, accumulated amortization	(6,768)	(4,479)
Below Market Lease, Net	7,886	9,865
Above-market ground lease
Liability
Cost	5,965	5,965
Accumulated Amortization	(266)	(128)
Net	$ 5,699	$ 5,837