Debt and Preferred Equity Investments - Roll Forward of Net Book Balances (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
SEC Schedule, 12-29, Real Estate Companies, Investment in Movement in Mortgage Loans on Real Estate [Roll Forward]
Balance at beginning of period	$ 1,076,542	$ 1,580,306
Redemptions/sales/syndications/equity ownership/amortization	(201,446)	(1,048,643)
Net change in loan loss reserves	6,583	(11,463)
Balance at end of period	1,088,723	1,076,542
Debt investment
SEC Schedule, 12-29, Real Estate Companies, Investment in Movement in Mortgage Loans on Real Estate [Roll Forward]
Originations/fundings/accretion	193,824	389,300
Preferred equity investments
SEC Schedule, 12-29, Real Estate Companies, Investment in Movement in Mortgage Loans on Real Estate [Roll Forward]
Originations/fundings/accretion	$ 13,220	$ 167,042