Loans and Allowance for Credit Losses - Summary of Activity in Allowance for Credit Losses (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - beginning balance	[1]	$ 70,280	$ 50,686	$ 63,845	$ 50,166
Total charge-offs		(12,862)	(6,182)	(30,959)	(13,968)
Total recoveries		9,077	6,889	15,859	11,955
Net recoveries (charge-offs)	[2]	(3,785)	707	(15,100)	(2,013)
Provision (benefit) for credit losses		8,476	7,759	12,514	10,999
Allowance for credit losses - ending balance	[3]	74,971	59,152	74,971	59,152
Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - beginning balance		0	0	13,712	0
Recreation [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - beginning balance				41,966
Total charge-offs		(9,166)	(5,074)	(21,756)	(10,141)
Total recoveries		3,282	3,615	6,053	7,125
Allowance for credit losses - ending balance		54,187		54,187
Home Improvement [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - beginning balance				11,340
Total charge-offs		(2,575)	(1,108)	(4,489)	(2,168)
Total recoveries		627	585	1,259	1,144
Allowance for credit losses - ending balance		16,447		16,447
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - beginning balance				1,049
Total charge-offs		(900)	0	(900)	(1,584)
Total recoveries		0	13	10	47
Allowance for credit losses - ending balance		2,518		2,518
Medallion [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - beginning balance				9,490
Total charge-offs		(221)	0	(3,814)	(75)
Total recoveries		5,168	$ 2,676	8,537	$ 3,639
Allowance for credit losses - ending balance		$ 1,819		$ 1,819

[1] Represents allowance prior to the adoption of ASU 2016-13.

[2] As of June 30, 2023, cumulative net charge-offs of loans and loan collateral in process of foreclosure in the medallion loan portfolio were $231.4 million, some of which may represent collection opportunities for the Company.

[3] As of June 30, 2023 and June 30, 2022, there were no allowance for credit losses and net charge-offs related to the strategic partnership loans.