No definition available.

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Cost of capital construction fund investments maturing maturing in third fiscal year following current fiscal year.

No definition available.

Name:	matx_CapitalConstructionFundInvestments
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Data Type:	xbrli:monetaryItemType
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Cost of capital construction fund investments maturing in remainder of current fiscal year.

No definition available.

Name:	matx_CapitalConstructionFundInvestmentsCostMaturitiesRemainderOfFiscalYear
Namespace Prefix:	matx_
Data Type:	xbrli:monetaryItemType
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Cost of capital construction fund investments maturing maturing in next fiscal year following current fiscal year.

No definition available.

Name:	matx_CapitalConstructionFundInvestmentsCostMaturitiesYearOne
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Fair value of investments made under capital construction fund.

No definition available.

Name:	matx_CapitalConstructionFundInvestmentsFairValue
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Data Type:	xbrli:monetaryItemType
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Fair value of capital construction fund investments maturing in remainder of current fiscal year.

No definition available.

Name:	matx_CapitalConstructionFundInvestmentsFairValueMaturitiesRemainderOfFiscalYear
Namespace Prefix:	matx_
Data Type:	xbrli:monetaryItemType
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Fair value of capital construction fund investments maturing maturing in next fiscal year following current fiscal year.

No definition available.

Name:	matx_CapitalConstructionFundInvestmentsFairValueMaturitiesYearOne
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Data Type:	xbrli:monetaryItemType
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Number of vessels under agreements for construction.

No definition available.

Name:	matx_NumberOfVesselsUnderAgreementForConstruction
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Data Type:	xbrli:integerItemType
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CAPITAL CONSTRUCTION FUND - INVESTMENT MATURITY (Details) $ in Millions	Jun. 30, 2026 USD ($) item	Dec. 31, 2025 USD ($)	Jun. 30, 2025 USD ($)	Dec. 31, 2024 USD ($)
CAPITAL CONSTRUCTION FUND
Remainder of 2026	$ 59.6
2027	52.5
Total CCF investments	112.1	$ 225.5	$ 326.6	$ 411.9
Remainder of 2026	59.6
2027	52.6
Total CCF investments	$ 112.2
Number of vessels under agreements for construction \| item	3