Amount to be repaid to the counterparty to the repurchase agreement when the carrying amount (or market value, if higher than the carrying amount) of securities or other assets sold under the repurchase agreement exceeds 10 percent of total assets.

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Significant Accounting Policies - Summary of Impact of Adoption on the Consolidated Balance Sheet (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 30, 2021	Jan. 01, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses	$ 146	$ 11		$ 55,031	$ 47,534	$ 43,858	$ 53,146
Reserve for repurchase liability	0			4,241
Increase in retained earnings	$ (82,182)			$ 92,320
Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Fair value adjustment to finance receivables			$ 23,584
Allowance for credit losses			55,031
Unamortized loan origination costs			(13,421)
Reserve for repurchase liability			4,241
Increase in retained earnings			$ 69,435