Commitments and Contingencies - Additional Information (Details) $ in Thousands, ft² in Millions	Mar. 31, 2019 USD ($) ft² Property
Other Commitments [Line Items]
Number of industrial properties | Property	458
Gross leasable area (GLA) of industrial properties | ft²	63.2
Development Activity
Other Commitments [Line Items]
Number of industrial properties | Property	14
Gross leasable area (GLA) of industrial properties | ft²	3.9
Estimated total investment | $	$ 297,500
Estimated total investment remaining to be funded | $	$ 193,800