Investments in Real Estate - Summary of Wholly Owned Industrial Properties Acquired (Details) $ in Thousands																					3 Months Ended	12 Months Ended
	Dec. 30, 2020 USD ($) ft² building	Dec. 05, 2020 USD ($) ft² building	Nov. 05, 2020 USD ($) ft² building	Oct. 26, 2020 USD ($) ft² building	Jul. 10, 2020 USD ($) ft² building	May 31, 2020 USD ($) ft² building	Apr. 17, 2020 USD ($) ft² building	Mar. 12, 2020 USD ($) ft² building	Dec. 19, 2019 USD ($) ft² building	Dec. 13, 2019 USD ($) ft² building	Nov. 15, 2019 USD ($) ft² building	Aug. 30, 2019 USD ($) ft² building	Aug. 29, 2019 USD ($) ft² building	Aug. 21, 2019 USD ($) ft² building	Aug. 19, 2019 USD ($) ft² building	Aug. 07, 2019 USD ($) ft² a building	May 28, 2019 USD ($) ft² building	Mar. 29, 2019 USD ($) a ft² building	Mar. 08, 2019 USD ($) a ft² building	Feb. 12, 2019 USD ($) ft² building	Dec. 31, 2019 a	Dec. 31, 2020 USD ($) ft² property building	Dec. 31, 2019 USD ($) a	Nov. 06, 2020 ft² building
Real Estate Properties [Line Items]
Number of properties									17													222
Area of real estate property | ft²									699,104
Purchase price									$ 273,610
Improved land parcels
Real Estate Properties [Line Items]
Number of properties | property																						25
Area of real estate property | ft²																						13,200,000
Asset Acquisitions 2020
Real Estate Properties [Line Items]
Asset acquisitions, assets acquired and liabilities assumed, net																						$ 100,400
Closing and acquisition costs																						1,600
Asset Acquisition, Intangible Liabilities																						2,100
Asset acquisitions 2019
Real Estate Properties [Line Items]
Asset acquisitions, assets acquired and liabilities assumed, net																							$ 289,600
Closing and acquisition costs																						$ 6,000
Asset Acquisition, Intangible Liabilities																							$ (10,000)
Asset acquisitions 2019 | Improved land parcels
Real Estate Properties [Line Items]
Area of real estate property acquired | a																							22.6
Wholly Owned Properties | Asset Acquisitions 2020
Real Estate Properties [Line Items]
Number of properties | building																						6
Area of real estate property | ft²																						163,794
Purchase price																						$ 96,657
Wholly Owned Properties | Asset Acquisitions 2020 | Old Bayshore
Real Estate Properties [Line Items]
Number of properties | building								0
Area of real estate property | ft²								0
Purchase price								$ 11,784
Wholly Owned Properties | Asset Acquisitions 2020 | Old Bayshore | Improved land parcels
Real Estate Properties [Line Items]
Area of real estate property acquired | a																					2.7
Wholly Owned Properties | Asset Acquisitions 2020 | Gladwick
Real Estate Properties [Line Items]
Number of properties | building								1
Area of real estate property | ft²								65,670
Purchase price								$ 17,950
Wholly Owned Properties | Asset Acquisitions 2020 | 84th Kent
Real Estate Properties [Line Items]
Number of properties | building							0
Area of real estate property | ft²							0
Purchase price							$ 4,500
Wholly Owned Properties | Asset Acquisitions 2020 | 84th Kent | Improved land parcels
Real Estate Properties [Line Items]
Area of real estate property acquired | a																					2.8
Wholly Owned Properties | Asset Acquisitions 2020 | Hudson
Real Estate Properties [Line Items]
Number of properties | building						1
Area of real estate property | ft²						13,000
Purchase price						$ 5,611
Wholly Owned Properties | Asset Acquisitions 2020 | Starlite Street
Real Estate Properties [Line Items]
Number of properties | building					1
Area of real estate property | ft²					22,275
Purchase price					$ 6,300
Wholly Owned Properties | Asset Acquisitions 2020 | Aviation Blvd
Real Estate Properties [Line Items]
Number of properties | building				0
Area of real estate property | ft²				0
Purchase price				$ 10,000
Wholly Owned Properties | Asset Acquisitions 2020 | Aviation Blvd | Improved land parcels
Real Estate Properties [Line Items]
Area of real estate property acquired | a																					1.9
Wholly Owned Properties | Asset Acquisitions 2020 | Porter Street
Real Estate Properties [Line Items]
Number of properties | building			1
Area of real estate property | ft²			13,000
Purchase price			$ 4,400
Wholly Owned Properties | Asset Acquisitions 2020 | SE 32nd St
Real Estate Properties [Line Items]
Number of properties | building																								1
Area of real estate property | ft²																								39,000
Purchase price		$ 11,737
Wholly Owned Properties | Asset Acquisitions 2020 | Maple Street
Real Estate Properties [Line Items]
Number of properties | building		0
Area of real estate property | ft²		0
Purchase price		$ 9,750
Wholly Owned Properties | Asset Acquisitions 2020 | Maple Street | Improved land parcels
Real Estate Properties [Line Items]
Area of real estate property acquired | a																					2.5
Wholly Owned Properties | Asset Acquisitions 2020 | East Marginal
Real Estate Properties [Line Items]
Number of properties | building	0
Area of real estate property | ft²	0
Purchase price	$ 6,625
Wholly Owned Properties | Asset Acquisitions 2020 | East Marginal | Improved land parcels
Real Estate Properties [Line Items]
Area of real estate property acquired | a																					2.1
Wholly Owned Properties | Asset Acquisitions 2020 | McLaren
Real Estate Properties [Line Items]
Number of properties | building	1
Area of real estate property | ft²	11,348
Purchase price	$ 8,000
Wholly Owned Properties | Asset acquisitions 2019 | East Marginal
Real Estate Properties [Line Items]
Number of properties | building											0
Area of real estate property | ft²											0
Purchase price											$ 2,850
Wholly Owned Properties | Asset acquisitions 2019 | East Marginal | Improved land parcels
Real Estate Properties [Line Items]
Area of real estate property acquired | a																0.9
Wholly Owned Properties | Asset acquisitions 2019 | 81 First N Hackensack
Real Estate Properties [Line Items]
Number of properties | building																			0
Area of real estate property | ft²																			0
Purchase price																			$ 25,000
Wholly Owned Properties | Asset acquisitions 2019 | 81 First N Hackensack | Improved land parcels
Real Estate Properties [Line Items]
Area of real estate property acquired | a																			16.8
Wholly Owned Properties | Asset acquisitions 2019 | 48 3rd and 286 Central
Real Estate Properties [Line Items]
Number of properties | building																		1
Area of real estate property | ft²																		28,124
Purchase price																		$ 14,085
Wholly Owned Properties | Asset acquisitions 2019 | 48 3rd and 286 Central | Improved land parcels
Real Estate Properties [Line Items]
Area of real estate property acquired | a																		2.9
Wholly Owned Properties | Asset acquisitions 2019 | Minnesota and Tennessee
Real Estate Properties [Line Items]
Number of properties | building																	2
Area of real estate property | ft²																	119,089
Purchase price																	$ 47,775
Wholly Owned Properties | Asset acquisitions 2019 | 51 Kero
Real Estate Properties [Line Items]
Number of properties | building																0
Area of real estate property | ft²																0
Purchase price																$ 4,025
Wholly Owned Properties | Asset acquisitions 2019 | 51 Kero | Improved land parcels
Real Estate Properties [Line Items]
Area of real estate property acquired | a																2.0
Wholly Owned Properties | Asset acquisitions 2019 | Anderson
Real Estate Properties [Line Items]
Number of properties | building															5
Area of real estate property | ft²															53,016
Purchase price															$ 18,100
Wholly Owned Properties | Asset acquisitions 2019 | Auburn 400
Real Estate Properties [Line Items]
Number of properties | building														1
Area of real estate property | ft²														70,345
Purchase price														$ 9,450
Wholly Owned Properties | Asset acquisitions 2019 | Morgan
Real Estate Properties [Line Items]
Number of properties | building													2
Area of real estate property | ft²													195,598
Purchase price													$ 80,500
Wholly Owned Properties | Asset acquisitions 2019 | 20th Street
Real Estate Properties [Line Items]
Number of properties | building												1
Area of real estate property | ft²												92,884
Purchase price												$ 23,752
Wholly Owned Properties | Asset acquisitions 2019 | Slauson
Real Estate Properties [Line Items]
Number of properties | building												2
Area of real estate property | ft²												29,927
Purchase price												$ 5,331
Wholly Owned Properties | Asset acquisitions 2019 | Whelan
Real Estate Properties [Line Items]
Number of properties | building										1
Area of real estate property | ft²										50,305
Purchase price										$ 12,000
Wholly Owned Properties | Asset acquisitions 2019 | 917 Valley
Real Estate Properties [Line Items]
Number of properties | building									1
Area of real estate property | ft²									40,816
Purchase price									$ 6,725
Wholly Owned Properties | Asset acquisitions 2019 | 49th Street
Real Estate Properties [Line Items]
Number of properties | building																				1
Area of real estate property | ft²																				19,000
Purchase price																				$ 24,017