Represents maximum entity's contribution limit to the concerned pension trust during the reporting period.

No definition available.

Name:	kex_DefinedBenefitPlanMaximumContributionLimit
Namespace Prefix:	kex_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Refers to the defined contribution plan contribution as a percentage of the aggregate accumulated benefit obligation during the period.

+ References

No definition available.

+ Details

Name:	kex_DefinedContributionPlanContributionPercentageAggregateAccumulatedBenefitObligation
Namespace Prefix:	kex_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- 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

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

- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

+ Details

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

- Definition

Amount of payment for pension benefits. Excludes other postretirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3536-108585

+ Details

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

- Details

Name:	us-gaap_RetirementPlanTypeAxis=kex_SeafarersPensionTrustMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanTypeAxis=kex_CentralPensionFundOfTheInternationalUnionOfOperatingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Retirement Plans, Multiemployer Pension Plan and Defined Contribution Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Aggregate contributions to the plans	$ 17,247	$ 18,213	$ 24,077
Seafarers Pension Trust [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension contributions	$ 896	$ 877
Contribution percentage to defined contribution plan	100.00%
Maximum contribution limit	5.00%
CPF [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension contributions	$ 238
Contribution percentage to defined contribution plan	94.00%