XML 117 R103.htm IDEA: XBRL DOCUMENT v3.20.4

Fair Value of Assets and Liabilities - Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Parenthetical) (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Net change in unrealized gains (losses) on investments, net of tax	$ (82)	$ 1,013	$ 1,081

X

- Definition

Net change in unrealized gains losses net of tax.

+ References

No definition available.

+ Details

Name:	mfin_NetChangeInUnrealizedGainsLossesNetOfTax
Namespace Prefix:	mfin_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- References

No definition available.

+ Details

Name:	us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration