| Document and Entity Information | Mar. 31, 2020 |
| Document and Entity Information [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Mar. 31, 2020 |
| Entity File Number | 001-34187 |
| Entity Registrant Name | MATSON, INC. |
| Entity Incorporation, State or Country Code | HI |
| Entity Tax Identification Number | 99-0032630 |
| Entity Address, Address Line One | 1411 Sand Island Parkway |
| Entity Address, State or Province | HI |
| Entity Address, City or Town | Honolulu |
| Entity Address, Postal Zip Code | 96819 |
| City Area Code | 808 |
| Local Phone Number | 848-1211 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, without par value |
| Trading Symbol | MATX |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0000003453 |
| Amendment Flag | false |
