Segment Information - Summary of Third-party Asset Management and Real Estate Services (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information
Third-party real estate services revenue, excluding reimbursements	$ 24,150	$ 15,955
Reimbursements revenue	13,957	13,761
Third-party real estate services revenue, including reimbursements	38,107	29,716
Third-party real estate services expenses	28,936	28,814
Third-party real estate services revenue less expenses	9,171	902
Property management fees
Segment Reporting Information
Third-party real estate services revenue, excluding reimbursements	4,942	6,024
Asset management fees
Segment Reporting Information
Third-party real estate services revenue, excluding reimbursements	2,228	2,724
Development fees
Segment Reporting Information
Third-party real estate services revenue, excluding reimbursements	14,250	2,812
Development fees \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01
Segment Reporting Information
Revenue, Remaining Performance Obligation, Amount	$ 55,900
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	6 years
Leasing fees
Segment Reporting Information
Third-party real estate services revenue, excluding reimbursements	$ 860	1,747
Construction management fees
Segment Reporting Information
Third-party real estate services revenue, excluding reimbursements	172	1,013
Other service revenue
Segment Reporting Information
Third-party real estate services revenue, excluding reimbursements	$ 1,698	$ 1,635

Reimbursement Revenue

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- Definition

Revenue from Contract with Customer, Excluding Reimbursements

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Revenue from Contract with Customer, Including Reimbursements

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- Definition

The amount of third-party real estate services expenses.

+ References

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- Definition

The amount of third-party real estate services revenue less expenses.

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Amount of transaction price allocated to performance obligation that has not been recognized as revenue.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130556-203045

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Period in which remaining performance obligation is expected to be recognized as revenue, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130556-203045

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- Definition

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.

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