Loans Portfolio - Additional Information (Details) - USD ($)	1 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2021
Financing Receivable Allowance For Credit Losses [Line Items]
Loans Receivable Percentage	7.00%	5.60%	7.00%
Initial Maturity		3 years 3 months 18 days	3 years 1 month 6 days
Outstanding Principal Balance	$ 615,800,000	$ 366,500,000	$ 615,800,000
Interest recognized		15,300,000
Operating Income (Loss)		15,300,000
Loans receivable held-for-investment	6,131,825,000	6,407,305,000	6,131,825,000		$ 64,274,000
Provision for loan losses	6,000,000.0	9,000,000.0	6,000,000
Principal repayment received		81,700,000
Chargeoff		1,800,000
Financing receivable, allowance for credit Loss		300,000
Reversal provision for allowances for credit losses	6,000,000.0	9,000,000.0	6,000,000
Total allowance for loan losses	$ (6,000,000)	(67,010,000)	$ (6,000,000)
COVID 19 [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Total allowance for loan losses		$ 73,500,000
Held-to-maturity Securities
Financing Receivable Allowance For Credit Losses [Line Items]
Initial Maturity		1 month 6 days	9 months 18 days
Receivable and interest rate	5.90%	6.70%	5.90%
Weighted average term to maturity		1 year 7 months 6 days	2 years 1 month 6 days
Senior Loans
Financing Receivable Allowance For Credit Losses [Line Items]
Loans receivable held-for-investment	$ 151,700,000	$ 48,100,000	$ 151,700,000	$ 347,200,000
Gain (Loss) on Senior Loan		(100,000)	(600,000)	100,000
Repayment proceeds of non-cash interest advances				$ 4,900,000
Entity Loan Modification Program
Financing Receivable Allowance For Credit Losses [Line Items]
Outstanding principal balance, carrying value	$ 15,000,000.0		$ 15,000,000.0
Entity Loan Modification Program | Senior Loans
Financing Receivable Allowance For Credit Losses [Line Items]
Outstanding principal balance for senior loan		$ 95,000,000.0
Loans Receivable Portfolio [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Initial Maturity		1 year 9 months 18 days	1 year 4 months 24 days
Receivable and interest rate	5.90%	5.60%	5.90%
Nonaccrual ninety day outstanding principal balance			$ 273,600,000
Nonaccrual ninety day percentage			4.10%
Interest recognized		$ 3,400	$ 0
Outstanding Principal Balance			382,300,000
Operating Income (Loss)		$ 3,400	$ 0
Loans Receivable And Interests In Loans Receivable Portfolio
Financing Receivable Allowance For Credit Losses [Line Items]
Receivable and interest rate	3.60%		3.60%
Loans Receivable And Interests In Loans Receivable Portfolio | Entity Loan Modification Program
Financing Receivable Allowance For Credit Losses [Line Items]
Outstanding principal balance	$ 233,500,000		$ 233,500,000
Floating Rate Loan
Financing Receivable Allowance For Credit Losses [Line Items]
Percentage Of Unpaid Principal Balance On Floating Rate Loans		1.10%