PENSION AND POST-RETIREMENT PLANS - MULTI-EMPLOYER DEFINED BENEFIT PLANS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Multiemployer Plans
Estimated benefit plan withdrawal obligations	$ 155.5
Pension Benefits | Hawaii Longshore Pension Plan | Green Zone
Multiemployer Plans
Contributions of Matson	12.9	$ 12.1	$ 11.9
Multiemployer Health and Benefit Plans
Multiemployer Plans
Contributions of Matson	41.2	37.7	37.7
Multi-employer defined benefit pension plans
Multiemployer Plans
Contributions of Matson	$ 34.8	32.7	33.8
Multi-employer defined benefit pension plans | Orange Zone
Multiemployer Plans
Expected funding deficiency period	6 years
Multi-employer defined benefit pension plans | Minimum | Green Zone
Multiemployer Plans
Funded status of multiemployer plan (as a percent)	80.00%
Multi-employer defined benefit pension plans | Maximum | Red Zone
Multiemployer Plans
Funded status of multiemployer plan (as a percent)	65.00%
Multi-employer defined benefit pension plans | Maximum | Yellow Zone
Multiemployer Plans
Funded status of multiemployer plan (as a percent)	80.00%
Multi-employer defined benefit pension plans | Maximum | Orange Zone
Multiemployer Plans
Funded status of multiemployer plan (as a percent)	80.00%
Multi-employer defined benefit pension plans | American Radio Association Pension Fund | Green Zone
Multiemployer Plans
Contributions of Matson	$ 1.0	1.0	1.1
Multi-employer defined benefit pension plans | Master Mates And Pilots Pension Plan | Green Zone
Multiemployer Plans
Contributions of Matson	3.7	3.6	3.8
Multi-employer defined benefit pension plans | Masters, Mates and Pilots Adjustable Pension Plan | Green Zone
Multiemployer Plans
Contributions of Matson	2.1	2.0	2.1
Multi-employer defined benefit pension plans | MEBA Pension Trust - Defined Benefit Plan | Green Zone
Multiemployer Plans
Contributions of Matson	4.6	4.2	4.5
Multi-employer defined benefit pension plans | OCU Pension Trust Plan | Green Zone
Multiemployer Plans
Contributions of Matson	0.6	0.4	0.5
Multi-employer defined benefit pension plans | MFOW Supplementary Pension Plan | Yellow Zone
Multiemployer Plans
Contributions of Matson	0.1	0.1	0.1
Multi-employer defined benefit pension plans | SIU Pacific District Pension Plan | Green Zone
Multiemployer Plans
Contributions of Matson	1.3	1.3	1.5
Multi-employer defined benefit pension plans | Alaska Teamster - Employer Pension Plan | Red Zone
Multiemployer Plans
Contributions of Matson	3.8	3.9	4.0
Multi-employer defined benefit pension plans | All Alaska Longshore Pension Plan | Green Zone
Multiemployer Plans
Contributions of Matson	2.2	1.8	2.0
Multi-employer defined benefit pension plans | Western Conference of Teamsters Pension Plan | Green Zone
Multiemployer Plans
Contributions of Matson	2.3	2.1	2.1
Multi-employer defined benefit pension plans | Western Conference Of Teamsters Supplemental Benefit Trust | Green Zone
Multiemployer Plans
Contributions of Matson	0.1	0.1	0.1
Multi-employer defined benefit pension plans | OPEIU Local 153 Pension Plan | Red Zone
Multiemployer Plans
Contributions of Matson	$ 0.1	$ 0.1	$ 0.1