Organization of Medallion Financial Corp. and its Subsidiaries - Additional Information (Detail)	12 Months Ended
Dec. 31, 2018 USD ($) Medallion	Dec. 31, 2017 USD ($)
Subsidiary or Equity Method Investee [Line Items]
Purchase price for City of Chicago taxicab medallions out of foreclosure	$ 8,689,000
Number of medallions purchased out of foreclosure \| Medallion	159
Net realizable value of medallions	$ 4,305,000
Net Fair value of medallions		$ 7,450,000
Medallion Financing Trust I [Member]
Subsidiary or Equity Method Investee [Line Items]
Aggregate assets of trust	$ 36,141,000

Number of medallions.

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The total amount of cash and securities held by third party trustees pursuant to terms of debt instruments or other agreements as of the date of each statement of financial position presented, which can be used by the trustee only to pay the noncurrent portion of specified obligations.

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Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of reorganization value related to estimated net realizable value of asset dispositions. Reorganization value is the amount attributed to the reconstituted entity, as well as the expected net realizable value of those assets that will be disposed before reconstitution occurs.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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