Loans and Investments - Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance at beginning of period	$ 121,331	$ 138,447	$ 113,241	$ 148,329
Provision for credit losses (net of recoveries)	965	(6,913)	9,055	(16,795)
Allowance at end of period	122,296	131,534	122,296	131,534
Amount of loan loss recovery	1,500
Outstanding unfunded commitments on loans	1,250,000		1,250,000		$ 975,200
Accrued interest receivable related to loans	97,800		97,800		$ 58,300
Land
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance at beginning of period	77,918	78,057	77,970	78,150
Provision for credit losses (net of recoveries)	(8)	(45)	(60)	(138)
Allowance at end of period	77,910	78,012	77,910	78,012
Multifamily Portfolio
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance at beginning of period	27,958	30,160	18,707	36,468
Provision for credit losses (net of recoveries)	(675)	(2,093)	8,576	(8,401)
Allowance at end of period	27,283	28,067	27,283	28,067
Office
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance at beginning of period	7,031	7,822	8,073	1,846
Provision for credit losses (net of recoveries)	306	(95)	(736)	5,881
Allowance at end of period	7,337	7,727	7,337	7,727
Retail
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance at beginning of period	5,819	13,819	5,819	13,861
Provision for credit losses (net of recoveries)				(42)
Allowance at end of period	5,819	13,819	5,819	13,819
Student Housing
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance at beginning of period	161	2,365	636	4,078
Provision for credit losses (net of recoveries)	14	(542)	(461)	(2,255)
Allowance at end of period	175	1,823	175	1,823
Hotel Portfolio
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance at beginning of period	16	225	8	7,759
Provision for credit losses (net of recoveries)	2	(209)	10	(7,743)
Allowance at end of period	18	16	18	16
Healthcare
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance at beginning of period	3	3,866	8	3,880
Provision for credit losses (net of recoveries)	1	(3,851)	(4)	(3,865)
Allowance at end of period	4	15	4	15
Other Property
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance at beginning of period	2,425	2,133	2,020	2,287
Provision for credit losses (net of recoveries)	1,325	(78)	1,730	(232)
Allowance at end of period	$ 3,750	$ 2,055	$ 3,750	$ 2,055