Real Estate - Schedule of Acquisitions and Conversions (Details) - USD ($) $ in Thousands		3 Months Ended		12 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Business Acquisition [Line Items]
Purchase Price		$ 220,711		$ 194,966
New York, NY
Business Acquisition [Line Items]
Purchase Price	[1]	59,207
Fund V
Business Acquisition [Line Items]
Purchase Price				$ 168,646
Fund V | Canton Marketplace | Canton GA
Business Acquisition [Line Items]
Percent Acquired				100.00%
Purchase Price			$ 50,954
Fund V | Monroe Marketplace | PA
Business Acquisition [Line Items]
Percent Acquired			100.00%
Purchase Price			$ 44,796
Fund V | Monroe Marketplace Parcel | PA
Business Acquisition [Line Items]
Percent Acquired				100.00%
Purchase Price			$ 1,029
Fund V | Midstate | NJ
Business Acquisition [Line Items]
Percent Acquired				100.00%
Purchase Price				$ 71,867
Core Portfolio
Business Acquisition [Line Items]
Purchase Price		161,504		26,320
Core Portfolio | 121 Spring Street - New York, NY
Business Acquisition [Line Items]
Purchase Price		$ 39,637
Core Portfolio | 121 Spring Street | New York, NY
Business Acquisition [Line Items]
Percent Acquired		100.00%
Core Portfolio | 8833 Beverly Boulevard | West Hollywood
Business Acquisition [Line Items]
Percent Acquired		100.00%
Purchase Price		$ 24,117
Core Portfolio | Williamsburg Collection | Brooklyn, NY
Business Acquisition [Line Items]
Purchase Price	[2]	97,750
Core Portfolio | Fourteen Street Portfolio
Business Acquisition [Line Items]
Purchase Price				$ 26,320
Core Portfolio | Fourteen Street Portfolio | Washington DC
Business Acquisition [Line Items]
Percent Acquired				100.00%
Fund III
Business Acquisition [Line Items]
Purchase Price		$ 59,207
Fund III | 640 Broadway | New York, NY
Business Acquisition [Line Items]
Percent Acquired	[1]	100.00%

[1] The entity was previously accounted for as an equity method investment until an affiliate of Fund III acquired the venture partner's interest in a foreclosure action. Fund III now indirectly owns 100% of the entity and consolidates it (Note 4).

[2] The Williamsburg Collection entity is a variable interest entity and the Company consolidates the entity because it is the entity's primary beneficiary. The Company invested $2.8 million in its 49.99% equity interest and, through a separate lending subsidiary, provided a $64.1 million first mortgage loan and a $30.9 million mezzanine loan to subsidiaries of the venture (such equity and loans have been eliminated in consolidation). Pursuant to the entity’s operating agreement, the venture partner has a one-time right to put its 50.01% interest in the entity (the "Williamsburg NCI", which is further described in Note 8) to the Company for fair value at a future date. Given the preferred rate of return of the Company embedded in its equity interests and the accruing debt senior to the equity, the Company did not attribute any initial redemption value to the Williamsburg NCI and recognized a gain on bargain purchase, which is included in Realized and unrealized holding gains on investments and other in the consolidated statements of income.