Investment in Real Estate Inestment in Real Estate - Summary of Industrial Property Dispositions (Details) $ in Thousands, ft² in Millions		12 Months Ended
		Dec. 31, 2020 USD ($) ft² Property	Dec. 31, 2019 USD ($) ft² Property	Dec. 31, 2018 USD ($) ft² Property
Real Estate Properties [Line Items]
Number of industrial properties | Property		427
Gross leasable area (GLA) of industrial properties | ft²		62.8
Proceeds from sale of industrial properties	[1]	$ 153,351	$ 315,768	$ 192,047
Gain on sale of real estate	[1]	86,751	$ 124,942	81,600
Sales Type Lease
Real Estate Properties [Line Items]
Gross leasable area (GLA) of industrial properties | ft²			0.6
Sales-type Lease, Selling Profit (Loss)		0	$ 8,606	0
Sales-type Lease, Lease Receivable		$ 0	$ 54,521	$ 0
Disposition Activity
Real Estate Properties [Line Items]
Number of industrial properties | Property	[2]	29	40	53
Gross leasable area (GLA) of industrial properties | ft²		1.9	5.9	2.6
Partial Disposition Activity
Real Estate Properties [Line Items]
Number of industrial properties | Property		1

[1] (B) Gross proceeds and gain on sale of real estate include the sale of several land parcels for the years ended December 31, 2019 and 2018. In addition, included in the above table for the year ended December 31, 2019, is 0.6 million square feet of GLA, gross proceeds of $54,521 and gain on sale of $8,606 related to the reclassification of a lease from an operating lease to a sales-type lease that was recorded as a lease receivable as of December 31, 2019 and collected during 2020. See Note 10 for additional information.

[2] (A) Included as one industrial property for each of the years ended December 31, 2020 and 2019 is the sale of multiple industrial condominium units.