Loans and Allowance for Loan Losses - Additional Information (Detail)		12 Months Ended
		Dec. 31, 2019 USD ($) TDR	Dec. 31, 2018 USD ($) TDR
Financing Receivable, Recorded Investment, Past Due [Line Items]
Weighted average loan-to-value ratio		190.00%	220.00%
Allowance for loan loss	[1]	$ 46,093,000	$ 36,395,000
Medallion [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of loans modified as TDRs defaulted | TDR		71	11
Allowance for loan loss		$ 25,410,000	$ 27,743,000
Recreation [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of loans modified as TDRs defaulted | TDR		294
Allowance for loan loss		$ 18,075,000	$ 6,856,000
Troubled Debt Restructuring Defaulted [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of loans modified as TDRs defaulted | TDR			1
TDR investment value			$ 218,000
Allowance for loan loss			$ 71,000
Troubled Debt Restructuring Defaulted [Member] | Medallion [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of loans modified as TDRs defaulted | TDR		4
TDR investment value		$ 1,023,000
Allowance for loan loss		$ 428,000
Troubled Debt Restructuring Defaulted [Member] | Recreation [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of loans modified as TDRs defaulted | TDR		213
TDR investment value		$ 1,905,000
Allowance for loan loss		$ 76,000

[1] Includes $3,173 of a general reserve as of December 31, 2019, for the Company, for current and performing medallion loans under 90 days past due, as an additional buffer against future losses, representing 7% of the total allowance, and 2.56% of the loans in question. This figure excludes $17,351 of a general reserve on loans at the Bank, which was netted against loan balances at consolidation on April 2, 2018. Subsequent to April 2, 2018, the Bank recorded general reserves benefit of $2,230.