Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)		3 Months Ended			6 Months Ended		12 Months Ended
	Jan. 01, 2023	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023	Dec. 31, 2021
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Interest-bearing funds deposited in other banks		$ 1,300,000			$ 1,300,000
Non-marketable securities		10,800,000			10,800,000		$ 11,400,000
Unrealized appreciation		4,700,000			4,700,000
Impact of equity investment		4,300,000			4,300,000
Past Due		69,714,000			69,714,000		81,013,000
Notes receivable net		2,340,968,000			2,340,968,000		2,176,412,000
Purchased of equity securities with readily determinable fair value								$ 2,000,000
Investment, Type [Extensible Enumeration]								us-gaap:EquitySecuritiesMember
Equity securities, fair value		1,700,000			1,700,000		1,700,000
Net loan origination costs					44,600,000		40,000,000
Net Amortization to income		2,300,000		$ 2,400,000	4,300,000	$ 4,300,000
Principal portion of loans serviced, fair value		$ 14,000,000			$ 14,000,000		14,000,000
Intangible assets useful life		20 years			20 years
Goodwill		$ 150,803,000			$ 150,803,000		150,803,000
Intangible assets, net		19,869,000			19,869,000		20,591,000
Amortization of intangible assets		362,000		363,000	723,000	723,000
Depreciation and amortization		100,000		100,000	200,000	200,000
Amortization expense		900,000		800,000	1,800,000	$ 1,500,000
Deferred costs		8,600,000			$ 8,600,000		$ 8,500,000
Potential dilutive common shares excluded from EPS computation					101,350	644,478
Stock based compensation award, Amount		$ 1,600,000		$ 1,200,000	$ 3,100,000	$ 2,200,000
Stock based compensation award per common share		$ 0.07		$ 0.05	$ 0.13	$ 0.1
Unrecognized compensation cost related to unvested stock options, restricted stock, restricted stock units, and performance share units		$ 8,400,000			$ 8,400,000
Unrecognized compensation cost related to unvested stock options and restricted stock, recognition period					11 months
Tier 1 leverage capital to total assets ratio		15.00%			15.00%
Tier 1 leverage capital ratio		16.10%			16.10%
Capital conversation buffer					2.50%		2.50%
New York Taxi Medallion [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Notes receivable net		$ 79,500			$ 79,500
Consumer Loan [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase in allowance for credit losses on loans	$ 13,700,000
Commercial Loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing receivable allowance for credit loss	$ 9,900,000
Restricted Shares [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stock based compensation award		0	296,178		296,178	316,483	399,793
Restricted Stock Units [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stock based compensation award					92,350	0
Performance Shares [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stock based compensation award		215,687			215,687		296,444
Stock based compensation award					215,687	296,444
Medallion Bank [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amortization of intangible assets							$ 0
90+ [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Past Due		$ 15,639,000			$ 15,639,000		16,837,000
90+ [Member] | Loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Past Due		$ 15,600,000			$ 15,600,000		$ 16,800,000
Total loans more than 90 days past due ,percentage		0.67%			0.67%		0.77%
Bank Holding Company Accounting [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net premium on investment securities					$ 100,000		$ 100,000
Minimum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Interest bearing loan term					5 years
Estimated useful life of fixed assets		3 years			3 years
Maximum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Interest bearing loan term					6 years
Investment securities Amortized to interest income		$ 100,000		$ 100,000	$ 100,000	$ 100,000
Estimated useful life of fixed assets		10 years			10 years