Schedule IV - Mortgage Loans on Real Estate Mortgage Loans on Real Estate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fixed rate	9.61%	8.82%
Prior Liens	$ 296,201
Face amount of Mortgages	3,195,576
Carrying Amount of Mortgages	3,138,792	$ 3,892,382	$ 3,521,985
Principal Amount of Mortgages Subject to Delinquent Principal or Interest	14,541
Total carrying amount of mortgages	3,181,957
Provision for loan losses	(43,165)
Principal balance of loans on non-accrual status	14,500
Aggregate cost for U.S. federal tax income purposes	3,200,000
Mortgage loans held for sale	3,138,792	3,892,382	3,521,985
Mortgage loan receivables held for investment, net, at amortized cost:
Mortgage loans receivable, beginning balance	3,892,382	3,521,985	2,343,070
Beginning balance, Allowance for credit losses	(20,755)	(31,752)	(41,507)
Origination of mortgage loan receivables	68,415	1,296,083	2,530,247
Repayment of mortgage loan receivables	(726,710)	(901,150)	(1,059,979)
Proceeds from sales of mortgage loan receivables		(29,151)	(305,649)
Non-cash disposition of loan via foreclosure	(91,408)	(10,235)	(81,289)
Realized gain on sale of mortgage loan receivables	(523)	(2,511)	8,398
Accretion/amortization of discount, premium and other fees	19,046	20,759	13,832
Charge-offs	2,700
Charge-offs	2,700	14,395	0
Release of provision for current expected credit loss, net	(25,096)	(3,711)	8,713
Release of provision for current expected credit loss, net			1,150
Release of provision for current expected credit loss, net	(25,110)	(3,398)	8,605
Mortgage loans receivable, ending balance	3,138,792	3,892,382	3,521,985
Ending balance, Allowance for credit losses	(43,165)	(20,755)	(31,752)
Mortgage loan  receivables held for sale
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Carrying Amount of Mortgages	26,900
Mortgage loans held for sale	26,900
Mortgage loan receivables held for investment, net, at amortized cost:
Mortgage loans receivable, ending balance	26,900
Total mortgage loan receivables held for investment, net, at amortized cost
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Carrying Amount of Mortgages	3,155,089	3,885,746	3,553,737
Mortgage loans held for sale	3,155,089	3,885,746	3,553,737
Mortgage loan receivables held for investment, net, at amortized cost:
Mortgage loans receivable, beginning balance	3,885,746	3,553,737	2,354,059
Beginning balance, Allowance for credit losses	(20,755)	(31,752)	(41,507)
Origination of mortgage loan receivables	68,415	1,234,765	2,309,888
Repayment of mortgage loan receivables	(726,710)	(901,082)	(1,059,796)
Proceeds from sales of mortgage loan receivables		0	(46,557)
Non-cash disposition of loan via foreclosure	(91,408)	(10,235)	(81,289)
Realized gain on sale of mortgage loan receivables	0	2,197
Accretion/amortization of discount, premium and other fees	19,046	20,759	13,832
Charge-offs	0	(14,395)
Charge-offs	2,700	14,395
Release of provision for current expected credit loss, net	(25,110)	(3,398)	8,605
Release of provision for current expected credit loss, net			1,150
Release of provision for current expected credit loss, net			8,605
Mortgage loans receivable, ending balance	3,155,089	3,885,746	3,553,737
Ending balance, Allowance for credit losses	$ (43,165)	$ (20,755)	(31,752)
Mortgage loan  receivables held for sale
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fixed rate	4.57%	4.57%
Carrying Amount of Mortgages	$ 26,868	$ 27,391	0
Mortgage loans held for sale	26,868	27,391	0
Mortgage loan receivables held for investment, net, at amortized cost:
Mortgage loans receivable, beginning balance	27,391	0	30,518
Origination of mortgage loan receivables	0	61,318	220,359
Repayment of mortgage loan receivables	0	(68)	(183)
Proceeds from sales of mortgage loan receivables		(29,151)	(259,092)
Realized gain on sale of mortgage loan receivables	(523)	(4,708)	8,398
Accretion/amortization of discount, premium and other fees	0	0
Charge-offs	0	0
Mortgage loans receivable, ending balance	26,868	$ 27,391	$ 0
First mortgage loan
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Prior Liens	0
Face amount of Mortgages	3,163,153
Carrying Amount of Mortgages	3,149,576
Principal Amount of Mortgages Subject to Delinquent Principal or Interest	14,541
Mortgage loans held for sale	3,149,576
Mortgage loan receivables held for investment, net, at amortized cost:
Mortgage loans receivable, ending balance	3,149,576
Second Mortgage
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Prior Liens	296,201
Face amount of Mortgages	32,423
Carrying Amount of Mortgages	32,381
Principal Amount of Mortgages Subject to Delinquent Principal or Interest	0
Mortgage loans held for sale	32,381
Mortgage loan receivables held for investment, net, at amortized cost:
Mortgage loans receivable, ending balance	$ 32,381
Office | First Mortgages individually greater than 3%
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fixed rate	9.19%
Prior Liens	$ 0
Face amount of Mortgages	110,800
Carrying Amount of Mortgages	110,551
Principal Amount of Mortgages Subject to Delinquent Principal or Interest	0
Mortgage loans held for sale	110,551
Mortgage loan receivables held for investment, net, at amortized cost:
Mortgage loans receivable, ending balance	$ 110,551
Office | First Mortgages individually greater than 3%
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fixed rate	8.99%
Prior Liens	$ 0
Face amount of Mortgages	224,175
Carrying Amount of Mortgages	223,676
Principal Amount of Mortgages Subject to Delinquent Principal or Interest	0
Mortgage loans held for sale	223,676
Mortgage loan receivables held for investment, net, at amortized cost:
Mortgage loans receivable, ending balance	$ 223,676
Industrial | First Mortgages individually greater than 3%
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fixed rate	8.49%
Prior Liens	$ 0
Face amount of Mortgages	114,331
Carrying Amount of Mortgages	114,330
Principal Amount of Mortgages Subject to Delinquent Principal or Interest	0
Mortgage loans held for sale	114,330
Mortgage loan receivables held for investment, net, at amortized cost:
Mortgage loans receivable, ending balance	$ 114,330
Mixed | First Mortgages individually greater than 3%
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fixed rate	9.46%
Prior Liens	$ 0
Face amount of Mortgages	145,840
Carrying Amount of Mortgages	144,752
Principal Amount of Mortgages Subject to Delinquent Principal or Interest	0
Mortgage loans held for sale	144,752
Mortgage loan receivables held for investment, net, at amortized cost:
Mortgage loans receivable, ending balance	144,752
Multi-Family, Office, Mixed, Industrial, Retail, Mobile Home Park, Hotel, Land | First Mortgages individually less than 3%
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Prior Liens	0
Face amount of Mortgages	2,568,007
Carrying Amount of Mortgages	2,556,267
Principal Amount of Mortgages Subject to Delinquent Principal or Interest	14,541
Mortgage loans held for sale	2,556,267
Mortgage loan receivables held for investment, net, at amortized cost:
Mortgage loans receivable, ending balance	$ 2,556,267
Multi-Family, Office, Mixed, Industrial, Retail, Mobile Home Park, Hotel, Land | Minimum | First Mortgages individually less than 3%
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fixed rate	4.25%
Multi-Family, Office, Mixed, Industrial, Retail, Mobile Home Park, Hotel, Land | Maximum | First Mortgages individually less than 3%
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fixed rate	13.74%
Retail, Office, Hotel | Subordinated Mortgages individually less than 3%
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Prior Liens	$ 296,201
Face amount of Mortgages	32,423
Carrying Amount of Mortgages	32,381
Principal Amount of Mortgages Subject to Delinquent Principal or Interest	0
Mortgage loans held for sale	32,381
Mortgage loan receivables held for investment, net, at amortized cost:
Mortgage loans receivable, ending balance	$ 32,381
Retail, Office, Hotel | Minimum | Subordinated Mortgages individually less than 3%
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fixed rate	10.00%
Retail, Office, Hotel | Maximum | Subordinated Mortgages individually less than 3%
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fixed rate	12.00%