Represents the contribution payable for the settlement of certain liabilities of the former parent company.

No definition available.

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

- Definition

Represents the cash outflow in the form of ordinary dividends to parent, generally out of earnings.

+ References

No definition available.

+ Details

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

- Definition

The total cash flow related to the issuance of stock to A&B.

+ References

No definition available.

+ Details

Name:	matx_ProceedsFromAndDistributionsToAAndBFromIssuanceOfCapitalStock
Namespace Prefix:	matx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Net expense recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

+ References

No definition available.

+ Details

Name:	matx_RelatedPartyTransactionNetExpensesFromTransactionsWithRelatedParty
Namespace Prefix:	matx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

This element represents equipment expense including depreciation, repairs, rentals, and service contract costs. This item also includes equipment purchases which do not qualify for capitalization in accordance with the entity's accounting policy. This item may also include furniture expenses.

+ References

No definition available.

+ Details

Name:	us-gaap_EquipmentExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Rental expense incurred for leased assets including furniture and equipment which has not been recognized in costs and expenses applicable to sales and revenues; for example, cost of goods sold or other operating costs and expenses.

+ References

No definition available.

+ Details

Name:	us-gaap_LeaseAndRentalExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash inflow from parent as a source of financing that is recorded as additional paid in capital.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 14

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3255-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 18

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_ProceedsFromContributionsFromParent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_RelatedPartyTransactionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 57

-Paragraph 2

-Subparagraph c

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1(e))

-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Related Parties

-URI http://asc.fasb.org/extlink&oid=16382449

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.6-07.1(c))

-URI http://asc.fasb.org/extlink&oid=6488393&loc=d3e606610-122999

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 07

-Paragraph b

-Subparagraph 1

-Article 6

+ Details

Name:	us-gaap_RevenueFromRelatedParties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Related Party Transactions: (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Related Party Transactions
Contributions to A&B			$ 151.4
A&B
Related Party Transactions
Vessel management services income	1.1		2.0
Lease expense to affiliate	(1.0)		(2.1)
Equipment and repair services expense and other	(0.9)		(1.4)
Related party expense, net	(0.8)		(1.5)
Contributions to A&B		0	151.4
Net contribution in relation to separation				4.3
Proceeds from and contributions to A&B from issuance of capital stock			21.7
Contributions from A&B		$ 0	$ 24.9