Name:	mgih_OrganizationandBusinessBackgroundDetailsLineItems
Namespace Prefix:	mgih_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Percentage of ordinary share.

No definition available.

Name:	mgih_PercentageOfOrdinaryShare
Namespace Prefix:	mgih_
Data Type:	dtr:percentItemType
Balance Type:	na
Period Type:	duration

The cash inflow from additional borrowings, net of cash paid to third parties in connection with debt origination.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 14
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-14

Name:	us-gaap_ProceedsFromDebtNetOfIssuanceCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Price of a single share of a number of saleable stocks of a company.

No definition available.

Name:	us-gaap_SharePrice
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

Number of shares of stock issued as of the balance sheet date, including shares that had been issued and were previously outstanding but which are now held in the treasury.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-SubTopic 10
-Topic 505
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-2