Loans and Allowance for Credit Losses - Summary of Activity in Allowance for Loan Losses (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - beginning balance	[1]	$ 83,827	$ 70,280	$ 84,235	$ 63,845
Charge-offs		(18,690)	(12,862)	(41,689)	(30,959)
Total recoveries		6,074	9,077	11,464	15,859
Net charge-offs	[2]	(12,616)	(3,785)	(30,225)	(15,100)
Provision for credit losses		18,577	8,476	35,778	12,514
Allowance for credit losses - ending balance	[3]	89,788	74,971	89,788	74,971
Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - beginning balance		0	0	0	13,712
Recreation [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - beginning balance				57,532
Charge-offs		(14,627)	(9,166)	(32,728)	(21,756)
Total recoveries		3,962	3,282	7,510	6,053
Allowance for credit losses - ending balance		65,140		65,140
Home Improvement [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - beginning balance				21,019
Charge-offs		(4,063)	(2,575)	(8,961)	(4,489)
Total recoveries		1,243	627	2,154	1,259
Allowance for credit losses - ending balance		18,388		18,388
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - beginning balance				4,148
Charge-offs		0	(900)	0	(900)
Total recoveries		0	0	20	10
Allowance for credit losses - ending balance		4,861		4,861
Taxi Medallion [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - beginning balance				1,536
Charge-offs		0	(221)	0	(3,814)
Total recoveries		869	$ 5,168	1,780	$ 8,537
Allowance for credit losses - ending balance		$ 1,399		$ 1,399

[1] 2023 beginning balance represents allowance prior to the adoption of ASU 2016-13.

[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.

[3] As of June 30, 2024 and June 30, 2023, there were no allowance for credit losses and net charge-offs related to the strategic partnership loans.