Expected funding deficiency period for determining zone status.

No definition available.

Name:	matx_MultiEmployerPlanExpectedFundingDeficiencyPeriod
Namespace Prefix:	matx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of contributions made to multiemployer plan by employer.

+ References

No definition available.

+ Details

Name:	matx_MultiemployerPlanContributionByEmployer
Namespace Prefix:	matx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the funded status of a multiemployer plan.

+ References

No definition available.

+ Details

Name:	matx_MultiemployerPlanFundedPercentage
Namespace Prefix:	matx_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of accumulated benefit obligation for multiemployer pension plan determined to be individually insignificant.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 5
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 7
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450678-114947

+ Details

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

- 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_MultiemployerPlansLineItems
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PENSION AND POST-RETIREMENT PLANS - MULTI-EMPLOYER DEFINED BENEFIT PLANS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Multiemployer Plans
Estimated benefit plan withdrawal obligations	$ 202.9
Pension Benefits \| Hawaii Longshore Pension Plan \| Green Zone
Multiemployer Plans
Contributions of Matson	11.1
Multiemployer Health and Benefit Plans
Multiemployer Plans
Contributions of Matson	34.7	$ 32.5	$ 32.8
Multi-employer defined contribution pension plans
Multiemployer Plans
Contributions of Matson	$ 31.0	28.4	27.3
Multi-employer defined contribution pension plans \| Orange Zone
Multiemployer Plans
Expected funding deficiency period	6 years
Multi-employer defined contribution pension plans \| Minimum \| Green Zone
Multiemployer Plans
Funded status of multiemployer plan (as a percent)	80.00%
Multi-employer defined contribution pension plans \| Maximum \| Red Zone
Multiemployer Plans
Funded status of multiemployer plan (as a percent)	65.00%
Multi-employer defined contribution pension plans \| Maximum \| Yellow Zone
Multiemployer Plans
Funded status of multiemployer plan (as a percent)	80.00%
Multi-employer defined contribution pension plans \| Maximum \| Orange Zone
Multiemployer Plans
Funded status of multiemployer plan (as a percent)	80.00%
Multi-employer defined contribution pension plans \| American Radio Association Pension Fund \| Green Zone
Multiemployer Plans
Contributions of Matson	$ 1.1	1.0	1.1
Multi-employer defined contribution pension plans \| Hawaii Terminals Multiemployer Pension Plan \| Yellow Zone
Multiemployer Plans
Contributions of Matson		5.8	5.7
Multi-employer defined contribution pension plans \| Hawaii Stevedoring Multiemployer Retirement Plan \| Green Zone
Multiemployer Plans
Contributions of Matson		4.6	4.4
Multi-employer defined contribution pension plans \| Master Mates And Pilots Pension Plan \| Green Zone
Multiemployer Plans
Contributions of Matson	3.5	3.2	3.4
Multi-employer defined contribution pension plans \| Masters, Mates and Pilots Adjustable Pension Plan \| Green Zone
Multiemployer Plans
Contributions of Matson	2.0	1.8	1.9
Multi-employer defined contribution pension plans \| MEBA Pension Trust - Defined Benefit Plan \| Green Zone
Multiemployer Plans
Contributions of Matson	4.3	4.1	4.3
Multi-employer defined contribution pension plans \| OCU Pension Trust Plan \| Green Zone
Multiemployer Plans
Contributions of Matson	0.3	0.2	0.2
Multi-employer defined contribution pension plans \| MFOW Supplementary Pension Plan \| Yellow Zone
Multiemployer Plans
Contributions of Matson	0.1	0.1	0.1
Multi-employer defined contribution pension plans \| SIU Pacific District Pension Plan \| Green Zone
Multiemployer Plans
Contributions of Matson	1.4	1.3	1.5
Multi-employer defined contribution pension plans \| Alaska Teamster - Employer Pension Plan \| Red Zone
Multiemployer Plans
Contributions of Matson	3.6	3.3	1.9
Multi-employer defined contribution pension plans \| All Alaska Longshore Pension Plan \| Green Zone
Multiemployer Plans
Contributions of Matson	1.6	1.3	1.2
Multi-employer defined contribution pension plans \| Western Conference of Teamsters Pension Plan \| Green Zone
Multiemployer Plans
Contributions of Matson	1.9	1.6	1.5
Multi-employer defined contribution pension plans \| OPEIU Local 153 Pension Plan \| Red Zone
Multiemployer Plans
Contributions of Matson	$ 0.1	$ 0.1	$ 0.1