CAPITAL CONSTRUCTION FUND - INVESTMENT MATURITY (Details) $ in Millions	Dec. 31, 2025 USD ($) item	Dec. 31, 2024 USD ($)
CAPITAL CONSTRUCTION FUND
2026	$ 173.1
2027	52.4
Total CCF investments	225.5	$ 411.9
2026	173.6
2027	52.8
Total CCF investments	$ 226.4
Number of vessels under agreements for construction \| item	3

No definition available.

Name:	matx_CapitalConstructionFundAbstract
Namespace Prefix:	matx_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

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

No definition available.

Name:	matx_CapitalConstructionFundInvestments
Namespace Prefix:	matx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

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

No definition available.

Name:	matx_CapitalConstructionFundInvestmentsCostMaturitiesYearOne
Namespace Prefix:	matx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

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

No definition available.

Name:	matx_CapitalConstructionFundInvestmentsCostMaturitiesYearTwo
Namespace Prefix:	matx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Fair value of investments made under capital construction fund.

No definition available.

Name:	matx_CapitalConstructionFundInvestmentsFairValue
Namespace Prefix:	matx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Fair value of capital construction fund investments maturing maturing in next fiscal year following current fiscal year.

No definition available.

Name:	matx_CapitalConstructionFundInvestmentsFairValueMaturitiesYearOne
Namespace Prefix:	matx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Fair value of capital construction fund investments maturing maturing in second fiscal year following current fiscal year.

No definition available.

Name:	matx_CapitalConstructionFundInvestmentsFairValueMaturitiesYearTwo
Namespace Prefix:	matx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Number of vessels under agreements for construction.

No definition available.

Name:	matx_NumberOfVesselsUnderAgreementForConstruction
Namespace Prefix:	matx_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant