Medallion Bank Preferred Stock - Additional Information (Detail) - USD ($)				12 Months Ended
	Dec. 17, 2019	Jul. 21, 2011	Feb. 27, 2009	Dec. 31, 2019
Capital Purchase Program [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
Preferred stock, liquidation preference per share				$ 1,000
U.S. Treasury Securities [Member] | Capital Purchase Program [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
US Treasury shares purchased		26,303
Series F Fixed-to-Floating Rate Non-cumulative Perpetual Preferred Stock [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
Initial public offering shares	1,840,000
Preferred stock, aggregate liquidation amount	$ 46,000,000
Preferred stock, net of liquidation amount	$ 42,485,000
Percentage of dividend payment rate	8.00%
Series F Fixed-to-Floating Rate Non-cumulative Perpetual Preferred Stock [Member] | SOFR [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
Percentage of liquidation rate basis	6.46%
Dividend description of variable rate basis	three-month Secured Overnight Financing Rate, or SOFR
Series ABC and D Non-cumulative Perpetual Preferred Stock [Member] | Capital Purchase Program [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
Aggregate purchase price			$ 21,498,000
Redemption of preferred stock				$ 4,000,000
Series E Senior Non-Cumulative Perpetual Preferred Stock [Member] | Capital Purchase Program [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
Percentage of dividend payment rate				9.00%
Aggregate purchase price		$ 26,303,000