Financial Instruments and Fair Value Measurements - Schedule of Items Measured at Fair Value on Nonrecurring Basis (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Real Estate [Line Items]
Impairment charges		$ 18,190	$ 0	$ 24,640	$ 0
Fair Value, Measurements, Nonrecurring
Real Estate [Line Items]
Impairment charges	[1],[2]			24,640
Fair Value, Measurements, Nonrecurring | Acadia Realty Trust
Real Estate [Line Items]
Impairment charges	[1],[2]			5,768
Fund III | New York, NY | Fair Value, Measurements, Nonrecurring | Level 3 Inputs Projections
Real Estate [Line Items]
Impairment charges	[2]			$ 7,240
Triggering Event				Reduced holding period
Fund III | New York, NY | Fair Value, Measurements, Nonrecurring | Level 3 Inputs Projections | Acadia Realty Trust
Real Estate [Line Items]
Impairment charges	[2]			$ 1,777
Fund IV | New York, NY | Fair Value, Measurements, Nonrecurring | Level 3 Inputs Projections
Real Estate [Line Items]
Impairment charges				$ 17,400
Triggering Event				Reduced holding period
Fund IV | New York, NY | Fair Value, Measurements, Nonrecurring | Level 3 Inputs Projections | Acadia Realty Trust
Real Estate [Line Items]
Impairment charges				$ 3,991

[1] An additional $0.4 million impairment related to the Company’s investment in Fifth Wall (Note 4) is included in Realized and unrealized holding gains (losses) on investments and other, in the Company’s Condensed Consolidated Statement of Operations.

[2] The fair value of the Fund III property, which was classified as held for sale, was based on the purchase and sale agreement, excluding selling costs. The fair value of the Fund IV property was estimated using a discounted cash flow model with a discount rate of 9.25% and a capitalization rate of 8.25%, resulting in a Level 3 fair value of $28.6 million as of the June 30, 2025 measurement date.