Subsequent Events (Details)	Aug. 05, 2020 shares
Subsequent Event [Member]
Stock Transaction [Abstract]
Number of shares issued on pro rata basis (in shares)	500,000

Number of shares distributed to its shareholders on a pro rata basis.

No definition available.

Name:	mghl_NumberOfSharesIssuedOnProRataBasis
Namespace Prefix:	mghl_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant