Finance Receivables - Original Product - Schedule of Finance Receivables for Original Product (Detail) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Accounts Notes And Loans Receivable [Line Items]
Finance receivables outstanding	$ 74,000	$ 258,000
Original Product [Member]
Accounts Notes And Loans Receivable [Line Items]
Reserve for credit losses	(60,000)	(142,000)
Finance receivables, net	14,000	116,000
Original Product [Member] | Funded During The Current Year [Member]
Accounts Notes And Loans Receivable [Line Items]
Finance receivables outstanding	14,000	25,000
Original Product [Member] | 1-2 Years Outstanding [Member]
Accounts Notes And Loans Receivable [Line Items]
Finance receivables outstanding	4,000	12,000
Original Product [Member] | 2-3 Years Outstanding [Member]
Accounts Notes And Loans Receivable [Line Items]
Finance receivables outstanding	2,000	9,000
Original Product [Member] | 3-4 Years Outstanding [Member]
Accounts Notes And Loans Receivable [Line Items]
Finance receivables outstanding	3,000	12,000
Original Product [Member] | Greater Than 4 Years Outstanding [Member]
Accounts Notes And Loans Receivable [Line Items]
Finance receivables outstanding	$ 51,000	$ 200,000