v3.25.3

DIVIDEND AND DISTRIBUTION (Details)	9 Months Ended
	Oct. 31, 2025
DIVIDEND AND DISTRIBUTION
Period after the close of each calendar quarter when the fiscal quarter ends	1 month

X

- References

No definition available.

+ Details

Name:	msb_DividendAndDistributionDisclosureAbstract
Namespace Prefix:	msb_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Represents the period after the close of each calendar quarter when the fiscal quarter of the entity ends.

+ References

No definition available.

+ Details

Name:	msb_PeriodAfterEachCalendarQuarterWhenEntityFiscalQuarterEnds
Namespace Prefix:	msb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration