XML 83 R65.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Long-Term Debt and Commitments, Long-Term Debt (Details) $ in Millions |  |  | 3 Months Ended | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | --- | ---
Apr. 30, 2018 USD ($) | Feb. 14, 2017 USD ($) | Oct. 03, 2021 Loan | Dec. 31, 2021 USD ($) qtr Offering Loan | Dec. 31, 2020 USD ($) | Dec. 31, 2019 USD ($) | Jun. 30, 2020 USD ($) | Jun. 23, 2015 USD ($) | May 09, 2014 USD ($)
Long-Term Debt and Commitments [Abstract] |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  | $ 937.0 | $ 934.2 |  |  |  |
Repayments of long-term debt |  |  |  | 1.2 | 290.1 | $ 88.2 |  |  |
Short-term borrowings |  |  |  | $ 80.0 | 0.0 |  |  |  |
Weighted average interest rate on short-term borrowings |  |  |  | 1.80% |  |  |  |  |
Maturities of Long-term Debt [Abstract] |  |  |  |  |  |  |  |  |
2022 |  |  |  | $ 0.8 |  |  |  |  |
2023 |  |  |  | 0.6 |  |  |  |  |
2024 |  |  |  | 548.6 |  |  |  |  |
2025 |  |  |  | 0.6 |  |  |  |  |
2026 |  |  |  | 0.6 |  |  |  |  |
Thereafter |  |  |  | 400.0 |  |  |  |  |
Interest Costs [Abstract] |  |  |  |  |  |  |  |  |
Interest costs |  |  |  | 42.1 | 40.7 | 46.0 |  |  |
Capitalized interest cost |  |  |  | 1.5 | 0.6 | $ 0.6 |  |  |
Sivomatic [Member] |  |  |  |  |  |  |  |  |
Long-Term Debt and Commitments [Abstract] |  |  |  |  |  |  |  |  |
Long-term debt assumed as part of acquisition | $ 10.7 |  |  |  |  |  |  |  |
Credit Agreement [Member] |  |  |  |  |  |  |  |  |
Long-Term Debt and Commitments [Abstract] |  |  |  |  |  |  |  |  |
Letters of credit excluded from financial covenant |  |  |  | $ 25.0 |  |  |  |  |
Number of quarters to maintain net leverage ratio under financial covenant | qtr |  |  |  | 4 |  |  |  |  |
Credit Agreement [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |
Long-Term Debt and Commitments [Abstract] |  |  |  |  |  |  |  |  |
Net leverage ratio |  |  |  | 3.50 |  |  |  |  |
Term Facility [Member] |  |  |  |  |  |  |  |  |
Long-Term Debt and Commitments [Abstract] |  |  |  |  |  |  |  |  |
Face amount |  |  |  |  |  |  |  |  | $ 1,560.0
Long-term debt |  |  |  |  |  |  |  | $ 1,378.0 |
Term Loan Facility - Variable Tranche [Member] |  |  |  |  |  |  |  |  |
Long-Term Debt and Commitments [Abstract] |  |  |  |  |  |  |  |  |
Long-term debt |  | $ 788.0 |  | $ 539.2 | 535.6 |  |  | 1,078.0 |
Decrease in basis spread on variable rate |  | (0.75%) |  |  |  |  |  |  |
Maturity date |  |  |  | Feb. 14, 2024 |  |  |  |  |
Required annual amortization |  |  |  | 1.00% |  |  |  |  |
Term Loan Facility - Variable Tranche [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |
Long-Term Debt and Commitments [Abstract] |  |  |  |  |  |  |  |  |
Interest rate |  |  |  | 0.75% |  |  |  |  |
Term Loan Facility - Variable Tranche [Member] | LIBOR [Member] |  |  |  |  |  |  |  |  |
Long-Term Debt and Commitments [Abstract] |  |  |  |  |  |  |  |  |
Basis spread on variable rate |  |  |  | 2.25% |  |  |  |  |
Term Loan Facility - Fixed Tranche [Member] |  |  |  |  |  |  |  |  |
Long-Term Debt and Commitments [Abstract] |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  |  |  |  |  | $ 300.0 |
Revolving Facility [Member] |  |  |  |  |  |  |  |  |
Long-Term Debt and Commitments [Abstract] |  |  |  |  |  |  |  |  |
Maximum borrowing capacity |  |  |  | $ 300.0 |  |  |  |  | $ 200.0
Long-term debt |  |  |  | $ 80.0 |  |  |  |  |
Maturity date |  |  |  | Apr. 18, 2023 |  |  |  |  |
Letters of credit outstanding |  |  |  | $ 10.6 |  |  |  |  |
Revolving Facility [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |
Long-Term Debt and Commitments [Abstract] |  |  |  |  |  |  |  |  |
Decrease in basis spread if net leverage ratio is less than certain thresholds |  |  |  | (0.25%) |  |  |  |  |
Revolving Facility [Member] | LIBOR [Member] |  |  |  |  |  |  |  |  |
Long-Term Debt and Commitments [Abstract] |  |  |  |  |  |  |  |  |
Basis spread on variable rate |  |  |  | 1.625% |  |  |  |  |
Senior Notes due 2028 [Member] |  |  |  |  |  |  |  |  |
Long-Term Debt and Commitments [Abstract] |  |  |  |  |  |  |  |  |
Face amount |  |  |  |  |  |  | $ 400.0 |  |
Long-term debt |  |  |  | $ 394.6 | 393.9 |  |  |  |
Maturity date |  |  |  | Jun. 30, 2028 |  |  |  |  |
Interest rate |  |  |  | 5.00% |  |  |  |  |
Guarantee amount |  |  |  | $ 50.0 |  |  |  |  |
Number of equity offerings where funds can be used to redeem percentage of aggregate principal amount | Offering |  |  |  | 1 |  |  |  |  |
Senior Notes due 2028 [Member] | Redemption of Notes for Cash Prior to July 1, 2023 [Member] |  |  |  |  |  |  |  |  |
Long-Term Debt and Commitments [Abstract] |  |  |  |  |  |  |  |  |
Redemption price percentage |  |  |  | 100.00% |  |  |  |  |
Senior Notes due 2028 [Member] | Redemption of Notes with Funds from One or More Equity Offerings Prior to July 1, 2023 [Member] |  |  |  |  |  |  |  |  |
Long-Term Debt and Commitments [Abstract] |  |  |  |  |  |  |  |  |
Redemption price percentage |  |  |  | 105.00% |  |  |  |  |
Percentage of aggregate principal amount that can be redeemed |  |  |  | 40.00% |  |  |  |  |
Senior Notes due 2028 [Member] | Redemption of Notes if Company Experiences Change of Control [Member] |  |  |  |  |  |  |  |  |
Long-Term Debt and Commitments [Abstract] |  |  |  |  |  |  |  |  |
Redemption price percentage |  |  |  | 101.00% |  |  |  |  |
Netherlands Term Loans [Member] |  |  |  |  |  |  |  |  |
Long-Term Debt and Commitments [Abstract] |  |  |  |  |  |  |  |  |
Repayments of long-term debt |  |  |  | $ 0.4 |  |  |  |  |
Number of term loans | Loan |  |  |  | 2 |  |  |  |  |
Number of term loans that matured | Loan |  |  | 1 |  |  |  |  |  |
Netherlands Term Loans [Member] | Euribor [Member] |  |  |  |  |  |  |  |  |
Long-Term Debt and Commitments [Abstract] |  |  |  |  |  |  |  |  |
Basis spread on variable rate |  |  | 2.00% |  |  |  |  |  |
Japan Loan Facilities [Member] |  |  |  |  |  |  |  |  |
Long-Term Debt and Commitments [Abstract] |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  | $ 3.0 | $ 4.1 |  |  |  |
Repayments of long-term debt |  |  |  | 0.8 |  |  |  |  |
Uncommitted Short-Term Bank Credit Lines [Member] |  |  |  |  |  |  |  |  |
Long-Term Debt and Commitments [Abstract] |  |  |  |  |  |  |  |  |
Maximum borrowing capacity |  |  |  | 25.9 |  |  |  |  |
Short-term borrowings |  |  |  | $ 0.0 |  |  |  |  |

X
- Definition The amount of letters of credit excluded from a financial covenant that requires the Company, if on the last day of any fiscal quarter loans or letters of credit were outstanding under the Revolving Facility to maintain a maximum net leverage ratio (as defined in the credit agreement) for the four fiscal quarters preceding such day. + References No definition available. + Details
Name: | mtx_DebtInstrumentFinancialCovenantExcludedLettersOfCredit
Namespace Prefix: | mtx_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The increase (decrease) in the percentage points added to the reference rate to compute the variable rate on the debt instrument if the net leverage ratio is less than certain thresholds. + References No definition available. + Details
Name: | mtx_DebtInstrumentFinancialCovenantIncreaseDecreaseInBasisSpreadIfNetLeverageRatioIsLessThanCertainThresholds
Namespace Prefix: | mtx_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of fiscal quarters under a financial covenant that requires the Company, if on the last day of any fiscal quarter loans or letters of credit were outstanding under the Revolving Facility, to maintain a maximum net leverage ratio (as defined in the credit agreement). + References No definition available. + Details
Name: | mtx_DebtInstrumentFinancialCovenantNumberOfQuartersToMaintainNetLeverageRatio
Namespace Prefix: | mtx_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Aggregate amount of the Company's or any of the Company's wholly owned domestic subsidiaries' long-term indebtedness unconditionally guaranteed on a senior unsecured basis under the debt instrument. + References No definition available. + Details
Name: | mtx_DebtInstrumentGuaranteeAmount
Namespace Prefix: | mtx_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The increase (decrease) in the percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
Name: | mtx_DebtInstrumentIncreaseDecreaseInBasisSpreadOnVariableRate
Namespace Prefix: | mtx_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The net leverage ratio, as defined in one of the financial covenants included in the credit agreement. + References No definition available. + Details
Name: | mtx_DebtInstrumentNetLeverageRatio
Namespace Prefix: | mtx_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

X
- Definition The required annual amortization of the original issue discount at the time the debt instrument was issued. + References No definition available. + Details
Name: | mtx_DebtInstrumentRequiredAnnualAmortization
Namespace Prefix: | mtx_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of equity offerings where funds can be used to redeem 40% of the aggregate principal amount of Notes prior to July 1, 2023. + References No definition available. + Details
Name: | mtx_NumberOfEquityOfferingsWhereFundsCanBeUsedToRedeemPercentageOfAggregatePrincipalAmount
Namespace Prefix: | mtx_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of term loans assumed by the Company as part of an acquisition. + References No definition available. + Details
Name: | mtx_NumberOfTermLoans
Namespace Prefix: | mtx_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of term loans that matured. + References No definition available. + Details
Name: | mtx_NumberOfTermLoansThatMatured
Namespace Prefix: | mtx_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of liabilities incurred by the acquirer as part of consideration transferred in a business combination. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=116859721&loc=d3e6578-128477 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 25 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6405-128476 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=120321790&loc=d3e6927-128479 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=116859721&loc=d3e6613-128477 + Details
Name: | us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1B -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=124435984&loc=d3e28551-108399 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=124429444&loc=SL124452920-239629 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 55 -Paragraph 69C -URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495737-112612 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 55 -Paragraph 69B -URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495735-112612 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1B -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Date when the debt instrument is scheduled to be fully repaid, in YYYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(2)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1B -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258 + Details
Name: | us-gaap_DebtInstrumentMaturityDate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage price of original principal amount of debt at which debt can be redeemed by the issuer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph e -URI http://asc.fasb.org/extlink&oid=123599511&loc=d3e64711-112823 + Details
Name: | us-gaap_DebtInstrumentRedemptionPricePercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of principal amount of debt redeemed. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentRedemptionPricePercentageOfPrincipalAmountRedeemed
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition Total interest costs incurred during the period and either capitalized or charged against earnings. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391 + Details
Name: | us-gaap_InterestCostsIncurred
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of interest capitalized, including amount of allowance for funds used during construction. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 835 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6501662&loc=d3e56162-110433 + Details
Name: | us-gaap_InterestCostsIncurredCapitalized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

X
- Definition The total amount of the contingent obligation under letters of credit outstanding as of the reporting date. + References No definition available. + Details
Name: | us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=123466204&loc=SL6031897-161870 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 55 -Paragraph 69C -URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495737-112612 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 55 -Paragraph 69B -URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495735-112612 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1D -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495340-112611 Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_LongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=123465755&loc=d3e1835-112601 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1E -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495348-112611 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04(a)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24072-122690 + Details
Name: | us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1E -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495348-112611 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04(a)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24072-122690 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=123465755&loc=d3e1835-112601 + Details
Name: | us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1E -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495348-112611 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=123465755&loc=d3e1835-112601 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04(a)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24072-122690 + Details
Name: | us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1E -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495348-112611 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=123465755&loc=d3e1835-112601 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04(a)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24072-122690 + Details
Name: | us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1E -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495348-112611 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04(a)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24072-122690 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=123465755&loc=d3e1835-112601 + Details
Name: | us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1E -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495348-112611 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04(a)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24072-122690 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=123465755&loc=d3e1835-112601 + Details
Name: | us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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

X
- Definition The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585 + Details
Name: | us-gaap_RepaymentsOfLongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 852 -SubTopic 10 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=84165509&loc=d3e56426-112766 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(19)(a)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)(a)(1)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(13)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 + Details
Name: | us-gaap_ShortTermBorrowings
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Weighted average interest rate of short-term debt outstanding calculated at point in time. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_ShortTermDebtWeightedAverageInterestRate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=mtx_SivomaticMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mtx_CreditAgreementFacilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mtx_TermFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mtx_TermLoanFacilityVariableTrancheMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mtx_TermLoanFacilityFixedTrancheMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mtx_RevolvingFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mtx_SeniorNotesDue2028Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentRedemptionPeriodAxis=mtx_RedemptionOfNotesForCashPriorToJuly12023Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentRedemptionPeriodAxis=mtx_RedemptionOfNotesWithFundsFromOneOrMoreEquityOfferingsPriorToJuly12023Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentRedemptionPeriodAxis=mtx_RedemptionOfNotesIfCompanyExperiencesChangeOfControlMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mtx_NetherlandsTermLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableRateAxis=mtx_EuroInterbankOfferedRateEuriborMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mtx_JapanLoanFacilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mtx_UncommittedShortTermBankCreditLinesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |