Loans and Allowance for Loan Losses - Summary of Performance Status of Loan (Detail) - USD ($) $ in Thousands		6 Months Ended	12 Months Ended
		Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Recorded Investment [Line Items]
Status of loans		$ 1,260,594	$ 1,160,855
Percentage of Nonperforming to Total		6.50%	5.38%
Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Status of loans		$ 1,178,669	$ 1,098,362
Non - Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Status of loans	[1]	81,925	62,493
Recreation [Member]
Financing Receivable, Recorded Investment [Line Items]
Status of loans		$ 786,785	$ 713,332
Percentage of Nonperforming to Total		0.68%	1.16%
Recreation [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Status of loans		$ 781,473	$ 705,070
Recreation [Member] | Non - Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Status of loans		5,312	8,262
Home Improvement [Member]
Financing Receivable, Recorded Investment [Line Items]
Status of loans		$ 282,072	$ 247,324
Percentage of Nonperforming to Total		0.05%	0.07%
Home Improvement [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Status of loans		$ 281,935	$ 247,139
Home Improvement [Member] | Non - Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Status of loans		137	185
Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Status of loans		$ 71,476	$ 69,767
Percentage of Nonperforming to Total		21.33%	17.00%
Commercial [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Status of loans		$ 56,230	$ 57,905
Commercial [Member] | Non - Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Status of loans		15,246	11,862
Medallion [Member]
Financing Receivable, Recorded Investment [Line Items]
Status of loans		$ 120,253	$ 130,432
Percentage of Nonperforming to Total		50.92%	32.34%
Medallion [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Status of loans		$ 59,023	$ 88,248
Medallion [Member] | Non - Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Status of loans		61,230	$ 42,184
Strategic Partnership [Member]
Financing Receivable, Recorded Investment [Line Items]
Status of loans		8
Strategic Partnership [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Status of loans		$ 8

[1] Includes $386 and $36,009 of TDRs as of June 30, 2020 and December 31, 2019, which are accruing and paying currently, but which are considered nonperforming loans under GAAP.