Refers to the engine power of a maritime vessel as measured in horsepower.

No definition available.

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- Definition

Refers to the number of branches the entity operates.

+ References

No definition available.

+ Details

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- Definition

Refers to the number of maritime (seagoing) vessels acquired.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
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- Definition

The average age of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References

No definition available.

+ Details

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Namespace Prefix:	kex_
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- Definition

Refers to the carrying capacity of tank barges as measured in number of barrels.

+ References

No definition available.

+ Details

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- 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

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- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6578-128477

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6613-128477

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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- Definition

Amount of equity interests of the acquirer, including instruments or interests issued or issuable in consideration for the business combination.

+ References

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The number of states the entity operates in as of the balance sheet date.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Investing Activities
-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3213-108585

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Balance Type:	credit
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Balance Type:
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=kex_BarrelTankBargesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=kex_InlandTowboatsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=kex_InlandTankBargesMember
Namespace Prefix:
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Period Type:

- Details

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ACQUISITIONS (Details)			6 Months Ended
ACQUISITIONS (Details)	Jul. 10, 2017 USD ($) Vessel bbl hp	Jun. 13, 2017 USD ($) Branch State	Jun. 30, 2017
Undisclosed Competitor [Member]
Business Acquisition [Line Items]
Cash paid for acquisition \| $	$ 68,000,000
Undisclosed Competitor [Member] \| Pressure Tank Barges [Member]
Business Acquisition [Line Items]
Number of maritime vessels acquired	9
Undisclosed Competitor [Member] \| Barrel Tank Barges [Member]
Business Acquisition [Line Items]
Number of maritime vessels acquired	4
Tank barge barrel capacity \| bbl	30,000
Undisclosed Competitor [Member] \| Inland Towboats [Member]
Business Acquisition [Line Items]
Number of maritime vessels acquired	3
Horsepower of inland towboats \| hp	1,320
Undisclosed Competitor [Member] \| Inland Tank Barges [Member]
Business Acquisition [Line Items]
Number of maritime vessels acquired	13
Average age of property			5 years
Stewart & Stevenson LLC [Member]
Business Acquisition [Line Items]
Purchase price \| $		$ 710,000,000
Stock consideration through issuance of company common stock \| $		$ 355,000,000
Number of branches \| Branch		42
Number of states having branches \| State		12