Investments in Unconsolidated Joint Ventures - Summary of Properties Contributed In Unconsolidated Joint Ventures (Detail)	3 Months Ended
	Mar. 31, 2020 USD ($)
Mark 302 JV [Member]
Related Party Transaction [Line Items]
Investment in joint venture revaluation date	Mar. 20, 2018	[1]
March 31, 2020	$ 90.0	[1]
March 31, 2020	$ 38.8	[1]
UTC Joint Venture [Member]
Related Party Transaction [Line Items]
Investment in joint venture revaluation date	May 18, 2018
March 31, 2020	$ 68.0
March 31, 2020	$ 28.3
West Hartford JV [Member]
Related Party Transaction [Line Items]
Investment in joint venture revaluation date	May 18, 2018	[2]
March 31, 2020	$ 20.3	[2]
March 31, 2020	$ (1.1)	[2]
Cockeysville JV [Member]
Related Party Transaction [Line Items]
Investment in joint venture revaluation date	Mar. 29, 2019	[3]
March 31, 2020	$ 12.5	[3]
March 31, 2020	$ 3.8	[3]
Tech Ridge JV [Member]
Related Party Transaction [Line Items]
Investment in joint venture revaluation date	Sep. 27, 2019	[4]
March 31, 2020	$ 3.0	[4]
March 31, 2020	$ 0.1	[4]

[1] The Mark 302 JV is subject to a revaluation upon the earlier of the first anniversary of project stabilization or December 31, 2020. The primary inputs in determining the Contribution Value for the Mark 302 JV are property operating income and total project costs and the Contribution Value will be recalculated to yield a pre-determined rate of return to the investment fund managed by Invesco Real Estate. The Contribution Value cannot be more than $105.0 million or less than $60.0 million, and the Gain (Loss) will not be more than $53.8 million or less than $8.8 million.

[2] The West Hartford JV was subject to (i) a revaluation upon the earlier of the first anniversary of project stabilization or December 31, 2019, and (ii) an adjustment based on the timing, method and magnitude of the reassessment of the property for real estate tax purposes between 2018 and 2022. As of December 31, 2019, the Company revalued the Contribution Value and recorded an additional loss of $2.3 million, and the Company does not expect there to be any additional revaluations.

[3] The Cockeysville JV is subject to revaluation if an affiliate of Greenberg Gibbons contributes another adjacent parcel of land (the “Additional Land Parcel”) to the Cockeysville JV if certain milestones are met with respect to entitling the Additional Land Parcel for residential use. If the Additional Land Parcel is contributed to the Cockeysville JV, the Company will record an increased investment in the Cockeysville JV in an amount equal to 50% of the fair value of the Additional Land Parcel at the time of contribution. The Contribution Value of the Cockeysville JV is based upon the Company’s assessment of the probability of the Additional Land Parcel being entitled for residential use.  The maximum Gain (Loss) is the fair value of the Additional Land Parcel at the time the Contribution Value is revalued, which cannot be less than $3.8 million.

[4] The Tech Ridge JV is subject to a revaluation primarily based upon the number of residential units constructed by the Tech Ridge JV.  The Contribution Value cannot be less than $2.75 million.