Customer Returns, Days After Original Sale Date

No definition available.

Name:	mtex_CustomerReturnsDaysAfterOriginalSaleDate
Namespace Prefix:	mtex_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of deferred commission associated with loyalty program as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	mtex_DeferredCommissionsRelatedToLoyaltyPrograms
Namespace Prefix:	mtex_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the average percentage of gross sales which are returned.

+ References

No definition available.

+ Details

Name:	mtex_PercentageOfSaleReturns
Namespace Prefix:	mtex_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of net sales shipped to customer by geographic region to consolidated net sales during the period.

+ References

No definition available.

+ Details

Name:	mtex_SalesRevenueGoodsPercentage
Namespace Prefix:	mtex_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Value of deferred revenue or cost to provide products or services, which is expected to be recognized in income or incurred within one year or the normal operating cycle, if longer, resulting from customer loyalty program. Excludes liability associated with frequent flier programs. Includes liability associated with customer loyalty programs for other businesses, for example, but is not limited to, hotels, supermarkets, credit card companies, automobile rental companies, and book sellers.

+ References

No definition available.

+ Details

Name:	us-gaap_CustomerLoyaltyProgramLiabilityCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of deferred revenue as of balance sheet date. Deferred revenue represents collections of cash or other assets related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 13.A.3)
-URI http://asc.fasb.org/extlink&oid=65893310&loc=d3e214044-122780

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 13.A.4(a).Q1)
-URI http://asc.fasb.org/extlink&oid=65893310&loc=d3e214044-122780

+ Details

Name:	us-gaap_DeferredRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of revenue recognized that was previously reported as deferred or unearned revenue.

+ References

+ Details

Name:	us-gaap_DeferredRevenueRevenueRecognized1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

Name:	us-gaap_SalesRevenueNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_ProductOrServiceAxis=mtex_ConsolidatedProductSalesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ProductOrServiceAxis=mtex_ConsolidatedPackSalesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ProductOrServiceAxis=mtex_ConsolidatedOtherIncludingFreightMember
Namespace Prefix:
Data Type:	na
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Period Type:

ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Revenue Recognition and Deferred Commissions (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue from External Customer [Line Items]
Revenue, Net		$ 173,600	$ 176,700
Sales Revenue Goods Percentage		100.00%	100.00%
Deferred revenue		$ 5,300	$ 8,600
Deferred revenue associated with customer loyalty programs		4,231	6,406	$ 7,033
Deferred commissions		$ 2,449	3,880
Customer returns, days after original sale date		90 days
Percentage of sale returns		1.50%
Deferred Revenue, Revenue Recognized	$ 6,600
Consolidated product sales [Member]
Revenue from External Customer [Line Items]
Revenue, Net		$ 170,200	$ 157,900
Sales Revenue Goods Percentage		98.00%	0.00%
Consolidated pack sales [Member]
Revenue from External Customer [Line Items]
Revenue, Net		$ 2,500	$ 14,200
Sales Revenue Goods Percentage		0.00%	0.00%
Consolidated other, including freight [Member]
Revenue from External Customer [Line Items]
Revenue, Net		$ 900	$ 4,600
Sales Revenue Goods Percentage		0.00%	0.00%