Funds Borrowed - Summary of Key Attributes of Various Borrowing Arrangements with Lenders (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Notes Payable [Line Items]
Average Interest Rate	2.89%	[1]
Notes Payable to Banks [Member]
Notes Payable [Line Items]
Note Amounts	$ 57,520
Balance outstanding	$ 50,899
Average Interest Rate	4.70%	[1]
Notes Payable to Banks [Member] | Parent Company [Member]
Notes Payable [Line Items]
Note Dates	Apr. 30, 2011
Note Dates	Aug. 31, 2014
Maturity Dates	Apr. 30, 2019
Maturity Dates	Sep. 30, 2020
Type	Term loans and demand notes secured by pledged loans	[2]
Note Amounts	$ 37,741	[2]
Balance outstanding	$ 37,741
Monthly Payment	Interest only	[3]
Average Interest Rate	5.10%
Notes Payable to Banks [Member] | Medallion Chicago [Member]
Notes Payable [Line Items]
Note Dates	Nov. 30, 2011
Note Dates	Dec. 31, 2011
Maturity Dates	Jun. 30, 2019
Type	Term loans secured by owned Chicago medallions	[4]
Note Amounts	$ 18,449
Balance outstanding	$ 11,828
Monthly Payment	134 of principal & interest
Average Interest Rate	3.50%
Notes Payable to Banks [Member] | Medallion Funding [Member]
Notes Payable [Line Items]
Note Dates	Nov. 30, 2018
Maturity Dates	Dec. 31, 2023
Note Amounts	$ 1,330
Balance outstanding	$ 1,330
Monthly Payment	70 principal & interest paid quarterly
Average Interest Rate	4.00%

[1] Weighted average contractual rate as of March 31, 2019.

[2] One note has an interest rate of Prime, one note has an interest rate of Prime plus 0.50%, one note has a fixed interest rate of 3.75%, one note has an interest rate of LIBOR plus 3.75%, and the other interest rates on these borrowings are LIBOR plus 2%.

[3] Various agreements call for remittance of all principal received on pledged loans subject to minimum monthly payments ranging from $12 to $75.

[4] Guaranteed by the Company.