Acquisitions - Estimated Fair Values of Assets and Liabilities Assumed (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) numberofaquisitiontransactions
Assets
Land and improvements	$ 80,269
Buildings and improvements	172,059
Deferred leasing costs and acquisition-related intangible assets	13,593
Total assets acquired	265,921
Liabilities
Acquisition-related intangible liabilities	8,921
Total liabilities assumed	8,921
Net assets and liabilities acquired	$ 257,000
Number of acquisitions | numberofaquisitiontransactions	2
Below-market leases acquired	$ 8,900
Weighted average amortization period of below-market leases	9 years 10 months
In-place leases [Member]
Assets
Deferred leasing costs and acquisition-related intangible assets	$ 11,800
Liabilities
Weighted average amortization period of above-market leases in years	1 year 4 months
Deferred leasing costs [Member]
Assets
Deferred leasing costs and acquisition-related intangible assets	$ 1,800
Liabilities
Weighted average amortization period of above-market leases in years	6 years 7 months