STOCK OPTIONS (Details Textual)	6 Months Ended
Jun. 30, 2021 shares
Number of share options exercised	9,600

Number of share options exercised in share based payment Arrangement,

No definition available.

Name:	hmg_NumberOfShareOptionsExercisedInShareBasedPaymentArrangement
Namespace Prefix:	hmg_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration