Loans and Allowance for Loan Losses - Schedule of Activity of Gross Loans (Detail) - USD ($)		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Schedule Of Gross Real Estate And Loan Activity [Line Items]
Gross loans, beginning balance	[1]			$ 1,461,622,000
Net recoveries (charge-offs)	[2]	$ (7,664,000)	$ 839,000	(9,677,000)	$ (12,100,000)
Transfer to loan collateral in process of foreclosure, net		(2,862,000)	(2,482,000)	(8,659,000)	(13,145,000)
Amortization of origination costs				(7,184,000)	(5,770,000)
Paid-in-kind interest				528,000	682,000
Gross loans, ending balance	[3]	1,821,095,000		1,821,095,000
Recreation [Member]
Schedule Of Gross Real Estate And Loan Activity [Line Items]
Gross loans, beginning balance	[1]			931,859,000
Transfer to loan collateral in process of foreclosure, net		(2,862,000)	(2,085,000)	(8,391,000)	(8,118,000)
Gross loans, ending balance	[3]	1,134,989,000		1,134,989,000
Home Improvement [Member]
Schedule Of Gross Real Estate And Loan Activity [Line Items]
Gross loans, beginning balance	[1]			438,931,000
Gross loans, ending balance	[3]	577,626,000		577,626,000
Medallion [Member]
Schedule Of Gross Real Estate And Loan Activity [Line Items]
Gross loans, beginning balance	[1]			14,046,000
Transfer to loan collateral in process of foreclosure, net		0	(397,000)	(268,000)	(5,027,000)
Gross loans, ending balance	[3]	13,973,000		13,973,000
Strategic Partnership [Member]
Schedule Of Gross Real Estate And Loan Activity [Line Items]
Gross loans, beginning balance	[1]			90,000
Net recoveries (charge-offs)				0	0
Gross loans, ending balance	[3]	773,000		773,000
Bank Holding Company Accounting [Member]
Schedule Of Gross Real Estate And Loan Activity [Line Items]
Gross loans, beginning balance		1,734,621,000	1,340,567,000	1,488,924,000	1,229,838,000
Loan originations		273,682,000	195,768,000	792,042,000	554,722,000
Principal payments, sales, maturities, and recoveries		(139,564,000)	(116,646,000)	(397,298,000)	(342,610,000)
Net recoveries (charge-offs)		(13,171,000)	839,000	(27,139,000)	(12,100,000)
Transfer to loan collateral in process of foreclosure, net		(2,862,000)	(2,482,000)	(8,659,000)	(13,145,000)
Amortization of origination costs		(2,514,000)	(2,146,000)	7,184,000	(5,868,000)
Amortization of loan premium		(150,000)	(150,000)	(450,000)	(2,032,000)
FASB origination costs		5,287,000	3,743,000	14,746,000	10,194,000
Paid-in-kind interest		181,000	188,000	528,000	682,000
Gross loans, ending balance		1,855,510,000	1,419,681,000	1,855,510,000	1,419,681,000
Bank Holding Company Accounting [Member] | Recreation [Member]
Schedule Of Gross Real Estate And Loan Activity [Line Items]
Gross loans, beginning balance		1,096,670,000	886,206,000	961,320,000	792,686,000
Loan originations		149,151,000	118,407,000	433,764,000	346,724,000
Principal payments, sales, maturities, and recoveries		(66,338,000)	(70,350,000)	(204,568,000)	(199,449,000)
Net recoveries (charge-offs)		(7,534,000)	335,000	(17,675,000)	(1,334,000)
Transfer to loan collateral in process of foreclosure, net		(2,862,000)	(2,085,000)	(8,391,000)	(8,118,000)
Amortization of origination costs		(3,008,000)	(2,532,000)	8,378,000	(7,171,000)
Amortization of loan premium		(60,000)	(60,000)	(180,000)	(161,000)
FASB origination costs		5,800,000	3,869,000	15,927,000	10,613,000
Paid-in-kind interest		0	0	0	0
Gross loans, ending balance		1,171,819,000	933,790,000	1,171,819,000	933,790,000
Bank Holding Company Accounting [Member] | Home Improvement [Member]
Schedule Of Gross Real Estate And Loan Activity [Line Items]
Gross loans, beginning balance		526,278,000	368,257,000	436,772,000	334,033,000
Loan originations		100,451,000	68,692,000	295,443,000	179,743,000
Principal payments, sales, maturities, and recoveries		(49,630,000)	(38,571,000)	(152,800,000)	(115,369,000)
Net recoveries (charge-offs)		(1,780,000)	239,000	(3,948,000)	(237,000)
Transfer to loan collateral in process of foreclosure, net		0	0	0	0
Amortization of origination costs		494,000	386,000	1,194,000	1,293,000
Amortization of loan premium		(90,000)	(90,000)	(270,000)	(256,000)
FASB origination costs		(513,000)	(139,000)	(1,181,000)	(433,000)
Paid-in-kind interest		0	0	0	0
Gross loans, ending balance		575,210,000	398,774,000	575,210,000	398,774,000
Bank Holding Company Accounting [Member] | Commercial [Member]
Schedule Of Gross Real Estate And Loan Activity [Line Items]
Gross loans, beginning balance		96,928,000	69,520,000	76,696,000	65,327,000
Loan originations		4,500,000	5,700,000	28,172,000	20,916,000
Principal payments, sales, maturities, and recoveries		(4,017,000)	(3,332,000)	(6,220,000)	(14,861,000)
Net recoveries (charge-offs)		(3,857,000)	0	(5,441,000)	0
Transfer to loan collateral in process of foreclosure, net		0	0	0	0
Amortization of origination costs		0	0	0	12,000
Amortization of loan premium		0	0	0	0
FASB origination costs		0	12,000	0	12,000
Paid-in-kind interest		181,000	188,000	528,000	682,000
Gross loans, ending balance		93,735,000	72,088,000	93,735,000	72,088,000
Bank Holding Company Accounting [Member] | Medallion [Member]
Schedule Of Gross Real Estate And Loan Activity [Line Items]
Gross loans, beginning balance		14,152,000	16,514,000	14,046,000	37,768,000
Loan originations		152,000	0	396,000	0
Principal payments, sales, maturities, and recoveries		(331,000)	(1,449,000)	(126,000)	(5,663,000)
Net recoveries (charge-offs)		0	265,000	(75,000)	(10,529,000)
Transfer to loan collateral in process of foreclosure, net		0	(397,000)	(268,000)	(5,027,000)
Amortization of origination costs		0	0	0	(2,000)
Amortization of loan premium		0	0	0	(1,615,000)
FASB origination costs		0	1,000	0	2,000
Paid-in-kind interest		0	0	0	0
Gross loans, ending balance		13,973,000	14,934,000	13,973,000	14,934,000
Bank Holding Company Accounting [Member] | Strategic Partnership [Member]
Schedule Of Gross Real Estate And Loan Activity [Line Items]
Gross loans, beginning balance		593,000	70,000	90,000	24,000
Loan originations		19,428,000	2,969,000	34,267,000	7,339,000
Principal payments, sales, maturities, and recoveries		(19,248,000)	(2,944,000)	(33,584,000)	(7,268,000)
Net recoveries (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	0	0
FASB origination costs		0	0	0	0
Paid-in-kind interest		0	0	0	0
Gross loans, ending balance		$ 773,000	$ 95,000	$ 773,000	$ 95,000

[1] Excludes loan premiums of $0.5 million and $26.8 million of capitalized loan origination costs.

[2] 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.

[3] Excludes loan premiums of $0.1 million and $34.3 million of capitalized loan origination costs.