Finance Receivables - Summary of Changes in Allowance for Credit Losses on Finance Receivables (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 11	$ 43,858	$ 55,031	$ 53,146
Effects of adopting fair value option			(55,031)	0
Provisions for credit losses on finance receivables	143	16,303	181	56,136
Finance receivables charged off	(8)	(15,277)	(35)	(70,073)
Recoveries of charge offs	0	2,650	0	8,325
Ending balance	$ 146	$ 47,534	$ 146	$ 47,534

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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- Definition

Amount of increase in allowance for credit loss on financing receivable from recovery.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of writeoff of financing receivable, charged against allowance for credit loss.

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Amount of credit loss expense (reversal of expense) for financing receivable from change in methodology.

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Amount of credit loss expense (reversal of expense) for financing receivable.

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