Summary of Significant Accounting Policies (Narrative) (Details) $ in Thousands	6 Months Ended	9 Months Ended	12 Months Ended
	Jun. 30, 2024 USD ($) Portfolio Segment	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)	Nov. 30, 2023 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Allowance for doubtful accounts as of December 31, 2022	$ 131		$ 132
Accumulated deficit	(228,730)		(233,026)
Reserve balance for credit loss	100		100
Deferred revenue	300		500
Nonaccrual loans	24,600		$ 0
Notes receivable, principal amount	35,200
Borrower's note balance	$ 23,100
Borrower's note balance, percentage	66.00%		62.00%
Due from borrower	$ 23,100
Number of distinct portfolio purchases and loan agreements | Portfolio	11
Amortization Cost				$ 51,600
Percentage of Amortization Cost				59.00%
Weighted average of years to the life of the Restructured Loans				1.50%
Allowances for Credit Losses	$ 1,100	$ 1,000
Notes Receivables	300
Equity method investments	22,380		$ 21,361
Other loans placed in nonaccrual status	1,500
Beginning balance of reserve for credit losses as of January 1, 2023	100		100
Allowance for credit loss	(466)
HGC Ltd.[Member]
Summary Of Significant Accounting Policies [Line Items]
Amortization Cost				$ 22,200
Percentage of Amortization Cost				57.00%
Equity method investments	800
Notes Receivable [Member]
Summary Of Significant Accounting Policies [Line Items]
Notes Receivables	5,700
Equity Method Investments [Member]
Summary Of Significant Accounting Policies [Line Items]
Equity method investments	$ 18,900
Consolidated [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of reporting segment | Segment	3
Accounting Standards Update 2022-02 [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of service revenue that is recognized over a period of time against total revenue	1.3905%
Note receivable outstanding	$ 500		700
Accounting Standards Update 2022-02 [Member] | Notes Receivable [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of service revenue that is recognized over a period of time against total revenue	3.30%
Accounting Standards Update 2022-02 [Member] | Equity Method Investments [Member]
Summary Of Significant Accounting Policies [Line Items]
Percentage of service revenue that is recognized over a period of time against total revenue	1.3905%
Credit loss rate	4.60%
Allowance for credit loss	$ 1,000		$ 900