Segment Information - Real Estate Investments, at Cost of Company's Reportable Segments (Additional Information) (Details) - a	9 Months Ended	12 Months Ended
Sep. 30, 2020	Dec. 31, 2019
3001-3003 and 3025 JFK Boulevard
Segment Reporting Information [Line Items]
Lease agreement term	99 years	99 years
Held-for-sale
Segment Reporting Information [Line Items]
Area of land (in acres)	35.2	35.2

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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Period Type:	duration