ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Company Organization (Details) - region	3 Months Ended	12 Months Ended
Mar. 31, 2018	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of regions in which company sells products	3	3

Represents the number of regions in which the company sells product.

No definition available.

Name:	mtex_NumberOfRegionsInWhichCompanySellsProducts
Namespace Prefix:	mtex_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration