Acquired Intangibles Assets and Liabilities - Amortization (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Amortization of acquired above and below-market leases, net			$ 126	$ 385
Amortization of all other identified intangible assets	$ 3,500	$ 3,100	9,900	$ 11,500
Estimated amortization of all other identified intangible assets
Net Carrying Value	85,242		85,242		$ 95,451
Maximum
Finite-Lived Intangible Assets [Line Items]
Amortization of acquired above and below-market leases, net	100	$ 100
Acquired favorable and unfavorable leases
Estimated amortization of acquired favorable and unfavorable leases Rental Revenue
2019 (October - December)	125		125
2020	659		659
2021	151		151
2022	51		51
2023	24		24
Thereafter	5		5
Total	1,015		1,015
Estimated amortization of acquired favorable and unfavorable leases Rental Expense
2019 (October - December)	(56)		(56)
2020	(216)		(216)
2021	(216)		(216)
2022	(216)		(216)
2023	(216)		(216)
Thereafter	(604)		(604)
Total	(1,524)		(1,524)
All other identified intangible assets
Estimated amortization of all other identified intangible assets
2019 (October - December)	3,214		3,214
2020	12,080		12,080
2021	10,580		10,580
2022	10,069		10,069
2023	10,065		10,065
Thereafter	28,519		28,519
Net Carrying Value	$ 74,527		$ 74,527