Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2020	Aug. 06, 2020
Document and Entity Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Jun. 30, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Entity Registrant Name	MEDALLION FINANCIAL CORP
Entity Central Index Key	0001000209
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		24,816,376
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Shell Company	false
Entity Incorporation, State or Country Code	DE
Entity File Number	001-37747
Entity Tax Identification Number	04-3291176
Entity Address, Address Line One	437 MADISON AVENUE, 38th Floor
Entity Address, City or Town	NEW YORK
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10022
City Area Code	212
Local Phone Number	328-2100
Common Stock [Member]
Document and Entity Information [Line Items]
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	MFIN
Security Exchange Name	NASDAQ
9.000% Senior Notes due 2021 [Member]
Document and Entity Information [Line Items]
Title of 12(b) Security	9.000% Senior Notes due 2021
Trading Symbol	MFINL
Security Exchange Name	NASDAQ