Fair Value Measurements - Additional Information (Details) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
Sep. 30, 2022	Sep. 30, 2022	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Money market funds	$ 139,100,000	$ 139,100,000	$ 199,300,000
Threshold period of delinquency		90 days
Estimated fair value of loans held for investment	$ 5,200,000,000	$ 5,200,000,000	$ 4,900,000,000
Weighted average gross spread percentage	3.46%	3.46%	3.39%
Weighted average maturity period		2 years 10 months 24 days	2 years 9 months 18 days
Transfers of financial assets or liabilities with in fair value hierarchy	$ 0	$ 0

Investment in short-term money-market instruments (such as commercial paper, banker's acceptances, repurchase agreements, government securities, certificates of deposit, and so forth) which are highly liquid (that is, readily convertible to known amounts of cash) and so near their maturity that they present an insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify as cash equivalents by definition. Original maturity means an original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant