Fair Value of Assets and Liabilities - Additional Information about Servicing Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Servicing Assets, Changes in fair value due to:
Fair value at beginning of period	$ 56,347
Fair value at end of period	67,726	$ 56,347
Fair Value, Measurements, Recurring
Servicing Assets, Changes in fair value due to:
Fair value at beginning of period	56,347	89,680
Issuances	69,075	33,990
Change in fair value, included in Marketplace Revenue	(56,561)	(58,730)
Other net changes included in Deferred Revenue	(1,135)	(8,593)
Fair value at end of period	$ 67,726	$ 56,347