Rental Property - Summary (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Property Subject to or Available for Operating Lease [Line Items]
Rental property, net	$ 4,038,197	$ 3,998,507
Deferred leasing intangible assets, accumulated amortization	267,553	241,304
Land
Property Subject to or Available for Operating Lease [Line Items]
Rental property, net	444,489	435,923
Buildings, net of accumulated depreciation of $292,467 and $254,458, respectively
Property Subject to or Available for Operating Lease [Line Items]
Rental property, net	2,833,458	2,787,234
Rental property, accumulated depreciation	292,467	254,458
Tenant improvements, net of accumulated depreciation of $23,724 and $21,487, respectively
Property Subject to or Available for Operating Lease [Line Items]
Rental property, net	38,638	38,339
Rental property, accumulated depreciation	23,724	21,487
Building and land improvements, net of accumulated depreciation of $130,170 and $111,688, respectively
Property Subject to or Available for Operating Lease [Line Items]
Rental property, net	239,214	232,456
Rental property, accumulated depreciation	130,170	111,688
Construction in progress
Property Subject to or Available for Operating Lease [Line Items]
Rental property, net	30,660	29,406
Deferred leasing intangibles, net of accumulated amortization of $267,553 and $241,304, respectively
Property Subject to or Available for Operating Lease [Line Items]
Rental property, net	$ 451,738	$ 475,149