Rental Property - Acquisitions (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($) ft² building	Mar. 31, 2020 USD ($) ft² building	Jun. 30, 2020 USD ($) ft² building
Business Acquisition [Line Items]
Area (in square feet)	91,800,000		91,800,000
Acquisitions 2020
Business Acquisition [Line Items]
Area (in square feet)	1,721,669		1,721,669
Number of Buildings Acquired | building			11
Business Combination, Consideration Transferred | $			$ 131,257
Acquistions Q1 2020
Business Acquisition [Line Items]
Area (in square feet)		1,599,389
Number of Buildings Acquired | building		9
Business Combination, Consideration Transferred | $		$ 119,343
Canton, MI - 1-10-20
Business Acquisition [Line Items]
Area (in square feet)		491,049
Number of Buildings Acquired | building		1
Business Combination, Consideration Transferred | $		$ 29,543
Rochester, NY - 1-10-20
Business Acquisition [Line Items]
Area (in square feet)		124,850
Number of Buildings Acquired | building		1
Business Combination, Consideration Transferred | $		$ 8,565
Hudson, WI - 2-6-20
Business Acquisition [Line Items]
Area (in square feet)		139,875
Number of Buildings Acquired | building		1
Business Combination, Consideration Transferred | $		$ 10,460
McClellan, CA - 2-6-20
Business Acquisition [Line Items]
Area (in square feet)		160,534
Number of Buildings Acquired | building		1
Business Combination, Consideration Transferred | $		$ 18,468
Richmond, VA - 2-6-20
Business Acquisition [Line Items]
Area (in square feet)		78,128
Number of Buildings Acquired | building		1
Business Combination, Consideration Transferred | $		$ 5,481
Muskego, WI - 2-7-20
Business Acquisition [Line Items]
Area (in square feet)		81,230
Number of Buildings Acquired | building		1
Business Combination, Consideration Transferred | $		$ 7,219
Warren, MI - 2-11-20
Business Acquisition [Line Items]
Area (in square feet)		311,123
Number of Buildings Acquired | building		1
Business Combination, Consideration Transferred | $		$ 23,141
Langhorne, PA - 3-9-20
Business Acquisition [Line Items]
Area (in square feet)		78,000
Number of Buildings Acquired | building		1
Business Combination, Consideration Transferred | $		$ 6,571
Tulsa, OK - 3-9-20
Business Acquisition [Line Items]
Area (in square feet)		134,600
Number of Buildings Acquired | building		1
Business Combination, Consideration Transferred | $		$ 9,895
Acquisitions Q2 2020
Business Acquisition [Line Items]
Area (in square feet)	122,280		122,280
Number of Buildings Acquired | building	2
Business Combination, Consideration Transferred | $	$ 11,914
Rancho Cordova, CA 6-11-20
Business Acquisition [Line Items]
Area (in square feet)	54,463		54,463
Number of Buildings Acquired | building	1
Business Combination, Consideration Transferred | $	$ 5,730
Schaumburg, IL 6-29-20
Business Acquisition [Line Items]
Area (in square feet)	67,817		67,817
Number of Buildings Acquired | building	1
Business Combination, Consideration Transferred | $	$ 6,184