Loans and Allowance for Credit Losses - Schedule of Activity of Gross Loans (Detail) - USD ($)		3 Months Ended		9 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Schedule Of Gross Real Estate And Loan Activity [Line Items]
Gross loans, beginning balance	[1]			$ 1,882,585,000
Net charge-offs	[2]	$ (10,370,000)	$ (7,664,000)	(25,469,000)	$ (9,677,000)
Transfer to loan collateral in process of foreclosure, net		(4,730,000)	(2,862,000)	(15,384,000)	(8,659,000)
Amortization of origination costs				(7,279,000)	(7,184,000)
Paid-in-kind interest				1,086,000	528,000
Gross loans, ending balance	[3]	2,163,877,000		2,163,877,000
Recreation [Member]
Schedule Of Gross Real Estate And Loan Activity [Line Items]
Gross loans, beginning balance	[1]			1,146,095,000
Transfer to loan collateral in process of foreclosure, net		(4,730,000)	(2,862,000)	(13,078,000)	(8,391,000)
Gross loans, ending balance	[3]	1,302,305,000		1,302,305,000
Home Improvement [Member]
Schedule Of Gross Real Estate And Loan Activity [Line Items]
Gross loans, beginning balance	[1]			628,877,000
Gross loans, ending balance	[3]	753,547,000		753,547,000
Medallion [Member]
Schedule Of Gross Real Estate And Loan Activity [Line Items]
Gross loans, beginning balance	[1]			13,571,000
Transfer to loan collateral in process of foreclosure, net		0	0	(2,306,000)	(268,000)
Gross loans, ending balance	[3]	3,927,000		3,927,000
Strategic Partnership [Member]
Schedule Of Gross Real Estate And Loan Activity [Line Items]
Gross loans, beginning balance	[1]			572,000
Net charge-offs				0	0
Gross loans, ending balance	[3]	1,841,000		1,841,000
Bank Holding Company Accounting [Member]
Schedule Of Gross Real Estate And Loan Activity [Line Items]
Gross loans, beginning balance		2,156,998,000	1,734,621,000	1,916,953,000	1,488,924,000
Loan originations		217,393,000	273,682,000	790,950,000	792,042,000
Principal payments, sales, maturities, and recoveries		(152,865,000)	(139,564,000)	(450,853,000)	(397,298,000)
Net charge-offs		(15,574,000)	(13,171,000)	(46,533,000)	(27,139,000)
Transfer to loan collateral in process of foreclosure, net		(4,730,000)	(2,862,000)	(15,384,000)	(8,659,000)
Amortization of origination costs		(2,612,000)	(2,514,000)	(7,279,000)	(7,184,000)
Amortization of loan premium			(150,000)		(450,000)
FASB origination costs, net		3,986,000	5,287,000	14,098,000	14,746,000
Paid-in-kind interest		442,000	181,000	1,086,000	528,000
Gross loans, ending balance		2,203,038,000	1,855,510,000	2,203,038,000	1,855,510,000
Bank Holding Company Accounting [Member] | Recreation [Member]
Schedule Of Gross Real Estate And Loan Activity [Line Items]
Gross loans, beginning balance		1,331,114,000	1,096,670,000	1,183,512,000	961,320,000
Loan originations		92,603,000	149,151,000	384,291,000	433,764,000
Principal payments, sales, maturities, and recoveries		(61,885,000)	(66,338,000)	(181,565,000)	(204,568,000)
Net charge-offs		(11,684,000)	(7,534,000)	(33,440,000)	(17,675,000)
Transfer to loan collateral in process of foreclosure, net		(4,730,000)	(2,862,000)	(13,078,000)	(8,391,000)
Amortization of origination costs		(3,259,000)	(3,008,000)	(9,177,000)	(8,378,000)
Amortization of loan premium			(60,000)		(180,000)
FASB origination costs, net		4,281,000	5,800,000	15,897,000	15,927,000
Paid-in-kind interest		0	0	0	0
Gross loans, ending balance		1,346,440,000	1,171,819,000	1,346,440,000	1,171,819,000
Bank Holding Company Accounting [Member] | Home Improvement [Member]
Schedule Of Gross Real Estate And Loan Activity [Line Items]
Gross loans, beginning balance		728,468,000	526,278,000	626,399,000	436,772,000
Loan originations		79,333,000	100,451,000	291,349,000	295,443,000
Principal payments, sales, maturities, and recoveries		(53,095,000)	(49,630,000)	(158,300,000)	(152,800,000)
Net charge-offs		(3,890,000)	(1,780,000)	(8,379,000)	(3,948,000)
Transfer to loan collateral in process of foreclosure, net		0	0	0	0
Amortization of origination costs		647,000	494,000	1,898,000	1,194,000
Amortization of loan premium			(90,000)		(270,000)
FASB origination costs, net		(955,000)	(513,000)	(2,459,000)	(1,181,000)
Paid-in-kind interest		0	0	0	0
Gross loans, ending balance		750,508,000	575,210,000	750,508,000	575,210,000
Bank Holding Company Accounting [Member] | Commercial [Member]
Schedule Of Gross Real Estate And Loan Activity [Line Items]
Gross loans, beginning balance		92,637,000	96,928,000	92,899,000	76,696,000
Loan originations		8,900,000	4,500,000	16,650,000	28,172,000
Principal payments, sales, maturities, and recoveries		(1,657,000)	(4,017,000)	(9,413,000)	(6,220,000)
Net charge-offs		0	(3,857,000)	(900,000)	(5,441,000)
Transfer to loan collateral in process of foreclosure, net		0	0	0	0
Amortization of origination costs		0	0	0	0
Amortization of loan premium			0		0
FASB origination costs, net		0	0	0	0
Paid-in-kind interest		442,000	181,000	1,086,000	528,000
Gross loans, ending balance		100,322,000	93,735,000	100,322,000	93,735,000
Bank Holding Company Accounting [Member] | Medallion [Member]
Schedule Of Gross Real Estate And Loan Activity [Line Items]
Gross loans, beginning balance		3,448,000	14,152,000	13,571,000	14,046,000
Loan originations		100,000	152,000	2,023,000	396,000
Principal payments, sales, maturities, and recoveries		(281,000)	(331,000)	(6,207,000)	(126,000)
Net charge-offs		0	0	(3,814,000)	(75,000)
Transfer to loan collateral in process of foreclosure, net		0	0	(2,306,000)	(268,000)
Amortization of origination costs		0	0	0	0
Amortization of loan premium			0		0
FASB origination costs, net		660,000	0	660,000	0
Paid-in-kind interest		0	0	0
Gross loans, ending balance		3,927,000	13,973,000	3,927,000	13,973,000
Bank Holding Company Accounting [Member] | Strategic Partnership [Member]
Schedule Of Gross Real Estate And Loan Activity [Line Items]
Gross loans, beginning balance		1,331,000	593,000	572,000	90,000
Loan originations		36,457,000	19,428,000	96,637,000	34,267,000
Principal payments, sales, maturities, and recoveries		(35,947,000)	(19,248,000)	(95,368,000)	(33,584,000)
Net charge-offs		0	0	0	0
Transfer to loan collateral in process of foreclosure, net		0	0	0	0
Amortization of origination costs		0	0	0	0
Amortization of loan premium			0		0
FASB origination costs, net		0	0	0	0
Paid-in-kind interest		0	0	0	0
Gross loans, ending balance		$ 1,841,000	$ 773,000	$ 1,841,000	$ 773,000

[1] Excludes $34.9 million of capitalized loan origination costs.

[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] Excludes $41.0 million of capitalized loan origination costs.