XML 101 R82.htm IDEA: XBRL DOCUMENT
v3.20.4

Contingencies (Details) | 12 Months Ended
--- | ---
Dec. 31, 2020 Case
Silica Cases [Member] |
Contingencies [Abstract] |
Number of lawsuits settled | 1
Asbestos Cases [Member] |
Contingencies [Abstract] |
Number of lawsuits settled | 0

X
- Definition Number of claims settled. + References No definition available. + Details
Name: | us-gaap_LossContingencyClaimsSettledNumber
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_LossContingencyInformationAboutLitigationMattersAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_LossContingenciesByNatureOfContingencyAxis=mtx_SilicaCasesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LossContingenciesByNatureOfContingencyAxis=mtx_AsbestosCasesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |