XML 82 R70.htm IDEA: XBRL DOCUMENT
v3.22.4

Retirement Plans, Weighted-Average Assumption Used to Determine Benefit Obligation (Details) | 12 Months Ended
--- | ---
Dec. 31, 2022 | Dec. 31, 2021
Pension Plan [Member] |  |  |  |
Weighted-average assumption used to determine benefit obligation at end of year [Abstract] |  |  |  |
Discount rate |  | 5.50% | [1] | 3.00%
Health care cost trend rate [Abstract] |  |  |  |
Initial rate |  | 0.00% |  | 0.00%
Ultimate rate |  | 0.00% |  | 0.00%
Pension Plan [Member] | Minimum [Member] |  |  |  |
Weighted-average assumption used to determine benefit obligation at end of year [Abstract] |  |  |  |
Discount rate | [1] |  |  | 3.00%
Pension Plan [Member] | Maximum [Member] |  |  |  |
Weighted-average assumption used to determine benefit obligation at end of year [Abstract] |  |  |  |
Discount rate | [1] |  |  | 3.10%
Pension Plan [Member] | Higman [Member] |  |  |  |
Weighted-average assumption used to determine benefit obligation at end of year [Abstract] |  |  |  |
Discount rate |  | 5.50% |  | 3.10%
SERP [Member] |  |  |  |
Weighted-average assumption used to determine benefit obligation at end of year [Abstract] |  |  |  |
Discount rate | [1] | 5.50% |  | 3.00%
Rate of compensation increase |  | 0.00% |  | 0.00%
Health care cost trend rate [Abstract] |  |  |  |
Initial rate |  | 0.00% |  | 0.00%
Ultimate rate |  | 0.00% |  | 0.00%
Other Postretirement Benefits [Member] |  |  |  |
Weighted-average assumption used to determine benefit obligation at end of year [Abstract] |  |  |  |
Discount rate | [1] | 5.50% |  | 3.00%
Rate of compensation increase |  | 0.00% |  | 0.00%
Health care cost trend rate [Abstract] |  |  |  |
Initial rate |  | 6.50% |  | 6.25%
Ultimate rate |  | 5.00% |  | 5.00%
Years to ultimate |  | 2029 |  | 2027
[1] | The 2022 discount rate was 5.5% for both the Kirby Pension Plan and the Higman Pension Plan. The 2021 discount rate was 3.0% for the Kirby Pension Plan and 3.1% for the Higman Pension Plan.

X
- Definition Defined Benefit Plan, Initial Health Care Cost Trend Rate + References No definition available. + Details
Name: | kex_DefinedBenefitPlanInitialHealthCareCostTrendRate
Namespace Prefix: | kex_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlanAssumedHealthCareCostTrendRatesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(1) -URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Weighted average rate increase of compensation, used to determine benefit obligation of defined benefit plan. Plan includes, but is not limited to, pay-related defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(2) -URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Ultimate trend rate for health care cost for defined benefit postretirement plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (l) -URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanUltimateHealthCareCostTrendRate1
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingBenefitObligationAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Year ultimate health care cost trend rate is expected to be reached, in YYYY format. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (l) -URI http://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanYearHealthCareCostTrendRateReachesUltimateTrendRate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:gYearListItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=kex_HigmanMarineIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |