DESCRIPTION OF THE BUSINESS (Details)	6 Months Ended
Jun. 30, 2020 facility segment	Jun. 30, 2019 segment
DESCRIPTION OF THE BUSINESS
Number of reportable segments \| segment	2	2
Ocean Transportation \| SSAT
DESCRIPTION OF THE BUSINESS
Ownership interest in SSAT (as a percent)	35.00%
Number of terminal facilities on which SSAT provided terminal and stevedoring services on the U.S. West Coast	8
MatNav \| SSAT
DESCRIPTION OF THE BUSINESS
Number of terminal facilities on which SSAT provided terminal and stevedoring services on the U.S. West Coast	4

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- Definition

Represents the number of ports terminal facilities on which the investee provides terminal and stevedoring services.

+ References

No definition available.

+ Details

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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

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- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8672-108599

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