Fair Value of Assets and Liabilities - Summary of Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis (Parenthetical) (Details) $ in Thousands	Dec. 31, 2025 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Equity investments measured on a non-recurring basis	$ 0

Fair value liabilities measured on non recurring basis obligations.

No definition available.

Name:	mfin_FairValueLiabilitiesMeasuredOnNonRecurringBasisObligations
Namespace Prefix:	mfin_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant