Loans and Allowance for Credit Losses - Summary of Activity in Allowance for Loan Losses (Parenthetical) (Detail) - USD ($) $ in Thousands		3 Months Ended			6 Months Ended
		Jun. 30, 2024		Jun. 30, 2023	Jun. 30, 2024		Jun. 30, 2023	Mar. 31, 2024	Dec. 31, 2023	[1]	Mar. 31, 2023	Dec. 31, 2022
Financing Receivable, Allowance for Credit Losses [Line Items]
Cumulative charges of loans and loan collateral process of foreclosure		$ 9,359	[1]	$ 16,803	$ 9,359	[1]	$ 16,803	$ 10,198	$ 11,772		$ 20,467	$ 21,819
Net charge-offs	[2]	(12,616)		$ (3,785)	(30,225)		(15,100)
Strategic Partnership [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Net charge-offs					0		$ 0
Medallion Bank [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Cumulative charges of loans and loan collateral process of foreclosure		173,300			173,300
New York Taxi Medallion [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Cumulative charges of loans and loan collateral process of foreclosure		$ 106,000			$ 106,000

[1] Includes financed sales of this collateral to third parties that are reported separately from the loan portfolio, of $5.3 million as of June 30, 2024 and $6.2 million as of December 31, 2023.

[2] As of June 30, 2024, cumulative net charge-offs of loans and loan collateral in process of foreclosure in the taxi medallion loan portfolio were $173.3 million, including $106.0 million related to loans secured by New York City taxi medallions, some of which may represent collection opportunities for the Company.