Loans and Allowance for Loan Losses - Summary of Activity in Allowance for Loan Losses (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses - beginning balance		$ 59,152	$ 46,946	$ 50,166	$ 57,548
Total charge-offs		(13,171)	(3,978)	(27,139)	(27,075)
Total recoveries		5,507	4,817	17,462	14,975
Net recoveries (charge-offs)	[1]	(7,664)	839	(9,677)	(12,100)
Provision (benefit) for loan losses		10,047	(337)	21,046	2,000
Allowance for loan losses - ending balance	[2]	61,535	47,448	61,535	47,448
Recreation [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses - beginning balance				32,435
Total charge-offs		(7,534)	(2,313)	(17,675)	(10,038)
Total recoveries		3,348	2,648	10,473	8,704
Allowance for loan losses - ending balance		40,768		40,768
Home Improvement [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses - beginning balance				7,356
Total charge-offs		(1,780)	(523)	(3,948)	(1,990)
Total recoveries		713	763	1,857	1,753
Allowance for loan losses - ending balance		10,208		10,208
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses - beginning balance				1,141
Total charge-offs		(3,857)	0	(5,441)	0
Total recoveries		0	0	47	0
Allowance for loan losses - ending balance		963		963
Medallion [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses - beginning balance				9,234
Total charge-offs		0	(1,142)	(75)	(15,047)
Total recoveries		1,446	$ 1,406	5,085	$ 4,518
Allowance for loan losses - ending balance		$ 9,596		$ 9,596

[1] As of September 30, 2022, cumulative net charge-offs of loans and loan collateral in process of foreclosure in the medallion loan portfolio were $252.5 million, some of which may represent collection opportunities for the Company.

[2] As of September 30, 2022 and September 30, 2021, there were no allowance for loan losses and net charge-offs related to the strategic partnership loans.