Loans and Allowance for Credit Losses - Summary of Activity in Allowance for Credit Losses (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - beginning balance	[1]	$ 74,971	$ 59,152	$ 63,845	$ 50,166
Total charge-offs		(15,574)	(13,171)	(46,533)	(27,139)
Total recoveries		5,204	5,507	21,064	17,462
Net charge-offs	[2]	(10,370)	(7,664)	(25,469)	(9,677)
Provision (benefit) for credit losses		14,532	10,047	27,045	21,046
Allowance for credit losses - ending balance	[3]	79,133	61,535	79,133	61,535
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		(11,684)	(7,534)	(33,440)	(17,675)
Total recoveries		2,651	3,348	8,705	10,473
Allowance for credit losses - ending balance		57,032		57,032
Home Improvement [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - beginning balance				11,340
Total charge-offs		(3,890)	(1,780)	(8,379)	(3,948)
Total recoveries		882	713	2,141	1,857
Allowance for credit losses - ending balance		17,300		17,300
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - beginning balance				1,049
Total charge-offs		0	(3,857)	(900)	(5,441)
Total recoveries		0	0	10	47
Allowance for credit losses - ending balance		3,114		3,114
Medallion [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses - beginning balance				9,490
Total charge-offs		0	0	(3,814)	(75)
Total recoveries		1,671	$ 1,446	10,208	$ 5,085
Allowance for credit losses - ending balance		$ 1,687		$ 1,687

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

[2] As of September 30, 2023, cumulative net charge-offs of loans and loan collateral in process of foreclosure in the taxi medallion loan portfolio were $201.7 million, some of which may represent collection opportunities for the Company.

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