Entity Address, City or Town Earnings available to common stockholders, basic, total Loss attributable to Kirby common stockholders - basic Net Income (Loss) Available to Common Stockholders, Basic Net earnings per share attributable to Kirby common stockholders: Earnings Per Share [Abstract] Revenues [Abstract] Segment Reporting Information, Revenue for Reportable Segment [Abstract] United States [Member] Domestic Tax Authority [Member] Cash flows from financing activities: Other segment disclosure [Abstract] Other segment disclosures [Abstract] Long-term Line of Credit, Total Credit facility, amount outstanding Long-Term Line of Credit Basis for Preparation of the Condensed Financial Statements Basis of Accounting [Text Block] Amendment Flag Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax, Total Pension and postretirement benefits Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax Subsequent Event Type [Domain] Three point four six series a notes due january nineteen two thousand thirty three. Three point Four Six Series A Notes Due January Nineteen Two Thousand Thirty Three [Member] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Goodwill, Ending Balance Goodwill, Beginning Balance Goodwill, Total Goodwill Goodwill Balance Marine transportation - 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. Marine Transportation [Member] Marine Transportation [Member] Operating lease right-of-use assets Income Tax Description [Abstract] Income Taxes [Abstract] Document Quarterly Report Schedule of Long-Term Debt Instruments [Table] Treasury stock purchases Treasury stock purchases Payments for Repurchase of Common Stock Less: imputed interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Letters of Credit [Member] Standby Letters of Credit [Member] Statement [Table] Operating lease liabilities - less current portion Total other comprehensive income, income tax provision Other Comprehensive Income (Loss), Tax, Total Total other comprehensive income, income tax provision Other Comprehensive Income (Loss), Tax U.S. Federal [Abstract] Federal Income Tax Expense (Benefit), Continuing Operations [Abstract] Other Postretirement Benefits [Member] Other Postretirement Benefits Plan [Member] Litigation Status [Axis] Operating Lease, Payments Operating cash outflow from operating leases Operating cash outflow from operating leases 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. Income Tax Disclosure [Line Items] Other [Member] Other Segments [Member] Guarantor Obligations, Nature [Axis] Business Acquisition [Axis] Proceeds from (Repayments of) Debt [Abstract] Shares Outstanding [Abstract] Shares outstanding [Abstract] Payments to Acquire Productive Assets, Total Capital expenditures Payments to Acquire Productive Assets Acquisitions Business Combination Disclosure [Text Block] Income Tax Authority [Domain] Income tax benefit Share-Based Payment Arrangement, Expense, Tax Benefit Product and Service [Axis] Represents to director plan of the equity-based compensation arrangement plan. Director Plan [Member] Director Plan [Member] Lessee, Operating Leases [Text Block] Leases Operating Lease, Weighted Average Remaining Lease Term Weighted average remaining lease term Total liabilities and equity Liabilities and Equity HAWAII Plan Name [Domain] Goodwill, Impaired, Accumulated Impairment Loss Accumulated impairment and amortization Entity Incorporation, State or Country Code Income Statement [Abstract] Accounts receivable: Accounts Receivable, after Allowance for Credit Loss, Current [Abstract] Reporting Segments [Member] Operating Segments [Member] Total current liabilities Liabilities, Current Other Assets [Abstract] Details of Other total assets [Abstract] 2025 Lessee, Operating Lease, Liability, to be Paid, Year Three Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Refers to the entity that is being acquired or purchased in a merger or acquisition. Higman Marine, Inc [Member] Higman [Member] Business Acquisition, Acquiree [Domain] Interest expense Interest Expense, Total Interest expense Interest Expense Short-term lease cost Short-Term Lease, Cost Treasury Stock, Shares, Ending Balance Treasury Stock, Shares, Beginning Balance Treasury Stock, Shares, Total Treasury Stock, Shares Treasury stock, shares (in shares) Guarantor Obligations [Line Items] Operating Lease, Weighted Average Discount Rate, Percent Weighted average discount rate Variable Rate [Axis] The service period of eligible participants of the employee pension plan who have reached the age of fifty that will be grandfathered and not be impacted by the amendment to the pension plan. Employee Pension Plan, Grandfathered Participants, Participant Service Period Who is Fifty Years Old Service period of participants who are age fifty not impacted by pension plan amendment Entity Small Business Number of reportable segments Number of Reportable Segments Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Total Cash and cash equivalents, beginning of year Cash and cash equivalents, end of period Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents Total current assets Assets, Current 2022 Lessee, Operating Lease, Liability, to be Paid, Remainder of Fiscal Year, Total Lessee, Operating Lease, Liability, to be Paid, Remainder of Fiscal Year Weighted Average Number of Shares Outstanding, Basic, Total Weighted Average Number of Shares Outstanding, Basic Weighted Average Number of Shares Outstanding, Basic (in Shares) City Area Code Represents to employee plan of the equity-based compensation arrangement plan. Employee Plan [Member] Employee Stock Award Plan [Member] Share-Based Payment Arrangement [Abstract] Total other assets Other Assets Document Period End Date Restricted Stock [Member] Issued guaranties Guarantor Obligations, Maximum Exposure, Undiscounted Net periodic benefit cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Segment Reporting Information, by Segment Schedule of Segment Reporting Information, by Segment [Table Text Block] Statistical Measurement [Axis] Impairments and other charges Other Asset Impairment Charges Amortization of net actuarial loss, net amount Amount, after tax, of reclassification adjustment from accumulated other comprehensive (income) loss for prior service cost (credit) and settlement of defined benefit plan. Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Settlement, Reclassification Adjustment from AOCI, after Tax Stockholders' Equity Attributable to Noncontrolling Interest, Ending Balance Stockholders' Equity Attributable to Noncontrolling Interest, Beginning Balance Stockholders' Equity Attributable to Noncontrolling Interest, Total Noncontrolling interests Amortization of net actuarial loss, gross amount Amount, before tax, of reclassification adjustment from accumulated other comprehensive (income) loss for prior service cost (credit) and settlement of defined benefit plan. Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Settlement, Reclassification Adjustment from AOCI, before Tax Total assets Total assets Assets Term of the guarantee or each group of financial instruments used to support performance by the company and its subsidiaries in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Term of Instrument Under Guarantor Obligations Guarantor obligations, expiration period Contract with Customer, Asset, after Allowance for Credit Loss, Total Contract with Customer, Asset, after Allowance for Credit Loss Contract assets Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] Costs and expenses: Costs and Expenses [Abstract] Long-term Debt, Excluding Current Maturities, Total Long-term debt, net - less current portion Long-Term Debt, Excluding Current Maturities Earnings Per Share, Diluted, Total Diluted (in dollars per share) Diluted Retirement Plan Type [Axis] Entity Address, Postal Zip Code Net earnings per share basic attributable to Kirby common stockholders: Earnings Per Share, Basic [Abstract] Document Fiscal Period Focus Pension Benefits [Member] Pension Plan [Member] Revolving Credit Facility [Member] Dilutive effect of stock options and restricted stock units (in shares) Incremental Common Shares Attributable to Share-based Payment Arrangements, Total Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Schedule of Guarantor Obligations [Table] Other income Other Nonoperating Income Operating Lease, Liability, Total Operating lease liabilities Operating Lease, Liability Net Cash Provided by (Used in) Financing Activities Net cash used in financing activities Refers to percentage of pension plan defined benefit plan cost increase limit during the period. Pension Plan Defined Benefit Plan Cost Increase Limit Percentage Pension plan defined benefit plan cost increase limit percentage Impairment of Long-Lived Assets to be Disposed of Statement of Financial Position [Abstract] Entity File Number Statement of Cash Flows [Abstract] Sublease income Sublease income Sublease Income Other comprehensive income, net of taxes: Other comprehensive income (loss), net of taxes: Foreign currency translation, gross amount Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax, Total Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax Retirement Plans Retirement Benefits [Text Block] Geographical [Domain] Statistical Measurement [Domain] Statement of Stockholders' Equity [Abstract] Lease, Cost [Table Text Block] Lease Cost Subsequent Events [Abstract] Proceeds from Stock Options Exercised Proceeds from exercise of stock options Long-Term Debt, Type [Axis] Number of shares of common stock determined by relating the portion of time within a reporting period that common shares have been issued and outstanding to the total time in that period. Weighted average common stock issued and outstanding Weighted average common stock issued and outstanding (in shares) Provision for deferred income taxes Deferred Income Tax Expense (Benefit), Total Deferred Income Tax Expense (Benefit) Deferred Income Tax Liabilities, Net, Total Deferred income taxes Deferred Income Tax Liabilities, Net Revenues Revenue from Contract with Customer [Text Block] Actuarial gains, gross amount Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax Gearbox repair Gearbox Repair [Member] Proceeds from Legal Settlements Proceeds from legal settlements Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Contract with Customer, Liability, Current Deferred revenues Provision for taxes on income [Abstract] Provision (benefit) for taxes on income [Abstract] Refers to coastal transportation of refined petroleum products and black oil. Coastal Transportation [Member] Coastal Transportation [Member] Credit Facility [Domain] Subsequent Events [Text Block] Subsequent Event Refers to revolving credit facility debt instruments. Revolving Credit Facility Due June Thirty Two Thousand Twenty One [Member] Credit line due September 30, 2021 [Member] Weighted Average Number of Shares Outstanding, Diluted, Total Weighted Average Number of Shares Outstanding, Diluted Weighted Average Number of Shares Outstanding, Diluted (in Shares) Credit Facility [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] operating leases related to weighted average discount rate and weighted average remaining lease term. Operating Leases, Weighted Average Discount Rate and Remaining Lease Term [Table Text Block] Operating Leases, Weighted Average Discount Rate and Remaining Lease Term Current Fiscal Year End Date Retirement Plans [Abstract] Defined Benefit Plan, Additional Information [Abstract] Other Assets, Noncurrent, Total Other assets Other Assets, Noncurrent Refers to a bank note payable. Bank Note Payable [Member] Bank Note Payable [Member] Ending balance Beginning balance Total equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Entity Address, Address Line One Repayments of Long-term Debt, Total Payments on long-term debt Repayments of Long-Term Debt Payments on long-term debt Refers to the senior notes debt instruments. Senior Notes Series B Due February Twenty Seven Two Thousand Twenty Three [Member] 3.29% Senior Notes Due February, 27 2023 [Member] Noncontrolling Interests [Member] Noncontrolling Interest [Member] Refers to the amount related to amortization of unearned compensation. Amortization of unearned compensation Amortization of unearned share-based compensation Proceeds from Lines of Credit, Total Proceeds from Lines of Credit Supplemental disclosures of cash flow information: Supplemental Cash Flow Information [Abstract] Provision for taxes on income Provision for taxes on income Total provision (benefit) for taxes on income Income Tax Expense (Benefit) Taxes on Income Income Tax Disclosure [Abstract] Disaggregation of Revenue [Abstract] Inland Tank Barges Inland Tank Barges Inland Tank Barges [Member] Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures, Total Issuance of stock for equity awards, net of forfeitures Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Number of Reporting Units Number of reporting units Costs and Expenses Total costs and expenses Fair Value Hierarchy and NAV [Axis] Other income (expense) included in net income that results in no cash inflows or outflows in the period. Includes noncash adjustments to reconcile net income (loss) to cash provided by (used in) operating activities that are not separately disclosed. Amortization of Major Maintenance Costs Amortization of major maintenance costs Goodwill and Intangible Assets Disclosure [Abstract] Contract with Customer, Liability, Revenue Recognized Revenue recognized Operating Income (Loss) Operating income Interest rate Debt Instrument, Interest Rate, Stated Percentage Refers to amount of general corporate expenses. General corporate expenses General corporate expenses Total long-term liabilities Liabilities, Noncurrent Additional Paid in Capital, Common Stock, Ending Balance Additional Paid in Capital, Common Stock, Beginning Balance Additional Paid in Capital Acquisitions of businesses and marine equipment Payments to Acquire Businesses, Net of Cash Acquired, Total Payments to Acquire Businesses, Net of Cash Acquired Refers to inland transportation of petrochemical feedstock, chemicals, pressurized products, refined petroleum products, certain black oil, agricultural chemicals and black oil, such as asphalt. Inland Transportation [Member] Inland Transportation [Member] Assets other than goodwill that contribute to the future cash flows of both the cash-generating unit under review and other cash-generating units. General corporate assets Deferred Income Taxes and Other Tax Receivable, Current Income tax receivable Entity Filer Category Cash paid during the period [Abstract] Cash paid (received) during the period: Entity Current Reporting Status Inventories - net Inventories - net Inventory, Net Current Current State and Local Tax Expense (Benefit) Inventories Inventory Disclosure [Text Block] Tax withholdings on equity award vesting (in shares) Share-Based Payment Arrangement, Shares Withheld for Tax Withholding Obligation Business Combinations [Abstract] Finite-Lived Intangible Assets, Net, Ending Balance Finite-Lived Intangible Assets, Net, Beginning Balance Finite-Lived Intangible Assets, Net, Total Other intangibles, net Net earnings per share diluted attributable to Kirby common stockholders: Earnings Per Share, Diluted [Abstract] Stockholders' Equity Attributable to Parent, Ending Balance Stockholders' Equity Attributable to Parent, Beginning Balance Total Kirby stockholders' equity Stockholders' Equity Attributable to Parent AOCI Attributable to Parent [Member] Accumulated Other Comprehensive Income [Member] Base Rate [Member] Base Rate [Member] Entity Tax Identification Number Common Stock, Value, Issued, Ending Balance Common Stock, Value, Issued, Beginning Balance Common Stock, Value, Issued, Total Common Stock, Value, Issued Common stock, $0.10 par value per share. Authorized 120 million shares, issued 65.5 million shares Consolidation Items [Axis] Retained Earnings (Accumulated Deficit), Ending Balance Retained Earnings (Accumulated Deficit), Beginning Balance Retained Earnings (Accumulated Deficit), Total Retained earnings Capital expenditures included in accounts payable Current and future cash outflow to pay for purchases of fixed assets that have occurred. Capital Expenditures Incurred, Paid and Not yet Paid Equity Components [Axis] Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net, Total Amount excluded on unamortized debt discounts and issuance costs Leases [Abstract] Long-term Debt [Abstract] Debt Instruments [Abstract] Disaggregation of Revenue [Table] KDS assets member. KDS Assets [Member] KDS Assets [Member] Entity Emerging Growth Company Interest cost Defined Benefit Plan, Interest Cost Goodwill [Roll Forward] Current Current Federal Tax Expense (Benefit) Goodwill [Line Items] Retirement Plan Type [Domain] Non-cash investing activity: [Abstract] Non-cash investing activity: Other Comprehensive Income Other Comprehensive Income, Noncontrolling Interest [Text Block] Debt Instrument, Carrying Value and Fair Value [Abstract] Carrying Value and Fair Value of Debt Outstanding [Abstract] Actuarial gains, income tax provision Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, Tax Lessee, Operating Lease, Liability, to be Paid [Abstract] Future Minimum Lease Payments Under Operating Leases [Abstract] Service cost Defined Benefit Plan, Service Cost Deferred Deferred Federal Income Tax Expense (Benefit) Retirement Benefits [Abstract] A credit facility arrangement that is repayable in quarterly installments in increasing percentages of the original principal amount of the loan. Term Loan Facility [Member] Term Loan [Member] Document Transition Report Taxes on Income Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block] Nonoperating Income (Expense), Total Other income Nonoperating Income (Expense) Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax [Abstract] Depreciation, Depletion and Amortization, Total Depreciation and amortization Impairment, Long-Lived Asset, Held-for-Use Impairment, Long-Lived Asset, Held-for-Use, Total Schedule of Segment Reporting Information, by Segment [Table] Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures, Total Issuance of stock for equity awards, net of forfeitures (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Amount payment to noncontrolling interest for return of investment during the period. Payments to Noncontrolling Interests for Return of Investment Return of investment to noncontrolling interest and other Contingencies and Commitments Commitments and Contingencies Disclosure [Text Block] Accumulated Other Comprehensive Income (Loss), Net of Tax, Total Accumulated other comprehensive income - net Accumulated Other Comprehensive Income (Loss), Net of Tax Accounts Receivable, after Allowance for Credit Loss, Current, Total Trade - less allowance for doubtful accounts Accounts Receivable, after Allowance for Credit Loss, Current Tabular disclosure of the profit or loss and total assets for other segment information. Schedule Of Other Segment Reporting Information By Segment [Table Text Block] Other Segment Reporting Information Entity Common Stock, Shares Outstanding Deferred State and Local Income Tax Expense (Benefit) Represents to stock and incentive plan of the equity-based compensation arrangement plan. Stock and Incentive Plan 2005 [Member] 2005 Stock and Incentive Plan [Member] Total other comprehensive income, net of taxes Other Comprehensive Income (Loss), Net of Tax Net earnings attributable to Kirby Net earnings attributable to Kirby Net Income (Loss) Attributable to Parent Operating Lease, Liability, Current Current portion of operating lease liabilities Additional Paid-in Capital [Member] Additional Paid-in Capital [Member] Refers to the senior notes debt instruments. Senior Notes Due March One Two Thousand Twenty Eight [Member] 4.2% Senior Notes Due March 1, 2028 [Member] Payments related to tax withholding for share-based compensation Payment, Tax Withholding, Share-Based Payment Arrangement Settlement Agreement [Member] Settlement agreement. Credit facility, expiration date Line of Credit Facility, Expiration Date Borrowings and Payments Under the Bank Credit Facilities Schedule of Line of Credit Facilities [Table Text Block] Entity Registrant Name Foreign currency translation adjustments Foreign currency translation, net amount Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Foreign currency translation, net amount The service period of eligible participants of the employee pension plan who will be grandfathered and not be impacted by the amendment to the pension plan. Employee Pension Plan, Grandfathered Participants, Service Period Service period of participants not impacted by pension plan amendment Cash and Cash Equivalents, at Carrying Value, Ending Balance Cash and Cash Equivalents, at Carrying Value, Beginning Balance Cash and Cash Equivalents, at Carrying Value, Total Cash and cash equivalents Earnings Per Share Earnings Per Share [Text Block] Maturity Date Debt Instrument, Maturity Date Share-based Payment Arrangement, Noncash Expense, Total Share-Based Payment Arrangement, Noncash Expense Amortization of share-based compensation Statement of Comprehensive Income [Abstract] Property, Plant and Equipment, Net, Beginning Balance Property, Plant and Equipment, Net, Ending Balance Property and equipment - net Property, Plant and Equipment, Net Debt Instrument, Unamortized Discount, Total Unamortized debt discounts and issuance costs Debt Instrument, Unamortized Discount Award Type [Domain] Statement [Line Items] Asset Impairment Charges [Text Block] Title of 12(b) Security Borrowings (payments) on bank credit facilities, net Borrowings (Payments) on bank credit facilities Proceeds from (Repayments of) Lines of Credit Restructuring Cost and Reserve [Line Items] Common Stock [Member] Common Stock [Member] Cash flows from operating activities: Equity Component [Domain] Payments for legal settlements Payments for Legal Settlements Revenue from Contract with Customer, Excluding Assessed Tax, Total Revenue from Contract with Customer, Excluding Assessed Tax Revenues by major source Total revenues Earnings before taxes on income Earnings (loss) before taxes on income Segment profit (loss) Earnings (loss) before taxes on income Distribution and services - 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. Distribution And Services [Member] Distribution and Services [Member] Entity Address, State or Province 2026 Lessee, Operating Lease, Liability, to be Paid, Year Four Geographical [Axis] Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Decrease in cash and cash equivalents Total comprehensive income, net of taxes Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Total comprehensive income, net of taxes Document Type Interest Paid, Excluding Capitalized Interest, Operating Activities Interest paid Interest paid Litigation Status [Domain] Amortization of actuarial loss (gain) Defined Benefit Plan, Amortization of Gain (Loss) Entity Shell Company Compensation cost Share-Based Payment Arrangement, Expense Segment Reporting Information [Line Items] Weighted average unvested restricted stock (in shares) Weighted Average Number of Shares, Restricted Stock Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Security Exchange Name Revenue from Contract with Customer [Abstract] Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Payments to Acquire Businesses, Gross Cash paid for acquisition Commitments and Contingencies Disclosure [Abstract] Income taxes payable Accrued Income Taxes, Current Tax withholdings on equity award vesting Share-Based Payment Arrangement, Decrease for Tax Withholding Obligation Operating lease cost Operating Lease, Cost Restricted Stock Units (RSUs) [Member] RSUs [Member] Lessee, Operating Lease, Liability, Maturity [Table Text Block] Future Minimum Lease Payments under Operating Leases New Accounting Pronouncements, Policy [Policy Text Block] Schedule of Defined Benefit Plans Disclosures [Table] Inventory, Work in Process, Gross Plan 2019 [Member] Plan 2019 [Member] Higman pension plan for 2019 year. Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Undistributed earnings reallocated to restricted shares Undistributed earnings reallocated to restricted shares Undistributed Earnings Reallocated To Restricted Shares Undistributed Earnings Reallocated To Restricted Shares. Contingencies and commitments Commitments and Contingencies Common Stock, Shares, Issued, Total Common Stock, Shares, Issued Common stock, shares issued (in shares) SERP [Member] Supplemental Employee Retirement Plan [Member] Undistributed earnings allocated to restricted shares Undistributed earnings allocated to restricted shares Undistributed Earnings (Loss) Allocated to Participating Securities, Diluted, Total Undistributed Earnings (Loss) Allocated to Participating Securities, Diluted Variable Rate [Domain] Current Federal, State and Local, Tax Expense (Benefit) [Abstract] Debt Instrument, Frequency of Periodic Payment Oil and Gas [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Segments [Domain] Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax, Total Foreign currency translation, income tax provision Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax Payments on bank credit facilities Repayments of Lines of Credit Other Supplemental Information about Operating Leases [Abstract] Other Supplemental Information about Operating Leases [Abstract] Accrued Liabilities, Current, Total Accrued liabilities Accrued Liabilities, Current Debt Instrument [Axis] Kirby stockholders' equity: Kirby stockholders' equity: Treasury Stock [Member] Treasury Stock [Member] Entity Address, Address Line Two Segments [Axis] Current Foreign Tax Expense (Benefit) Revenues: Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority Tax refund amount Award Type [Axis] Other Noncash Income (Expense), Total Other Other Noncash Income (Expense) Subsequent Event [Member] Subsequent Event [Member] Debt Instrument, Fair Value Disclosure, Total Debt Instrument, Fair Value Disclosure Fair value Earnings (loss) before taxes on income [Abstract] Line of credit facility repayment Line of credit facility repayment Carrying Values and Fair Values of Debt Outstanding Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Total lease payments Lessee, Operating Lease, Liability, to be Paid Entity Central Index Key Employee Stock Award Plan [Abstract] Stock Award Plan Information [Abstract] Net Income (Loss) Attributable to Parent [Abstract] Net Income (Loss) Attributable to Parent [Abstract] Costs incurred and are directly related to generating revenues and generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services, excludes selling, general and administrative expense. Costs Of Sales And Operating Expenses Costs of sales and operating expenses Refers to selling OEM replacement parts and new diesel engines, provides service mechanics and maintains facilities to overhaul and repair diesel engines and ancillary products for marine and on-highway transportation companies, mining and industrial companies. The Company provides engineering and field services, OEM replacement parts and safety-related products to power generation operators and to the nuclear industry, manufactures engine generator and pump packages for power generation operators and municipalities, offers power generation systems customized for specific commercial and industrial applications, and rents equipment including power generation systems, pumps, air compressors, fork lifts and railcar movers. Commercial and Industrial [Member] Commercial and Industrial [Member] Disaggregation of Revenue [Line Items] Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Ending Balance Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Beginning Balance Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Total Accumulated depreciation Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Consolidation Items [Domain] Shares available for future grants (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant Stock Award Plans Share-Based Payment Arrangement [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax [Abstract] Notes Payable to Bank, Current Bank notes payable Total lease cost Lease, Cost Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Right-of-use assets obtained in exchange for lease obligations Components of net periodic benefit cost [Abstract] Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract] Adjustments to reconcile net earnings to net cash provided by operations: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Retained Earnings [Member] Retained Earnings [Member] Unsecured Debt [Member] Segment Reporting [Abstract] Underlying Asset Class [Axis] Schedule of Goodwill [Table] SOFR [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Property, Plant and Equipment, Gross, Ending Balance Property, Plant and Equipment, Gross, Beginning Balance Property, Plant and Equipment, Gross, Total Property and equipment Property, Plant and Equipment, Gross Entity Interactive Data Current Intersegment Eliminations [Member] Other Other Receivables Undistributed earnings allocated to restricted shares Undistributed earnings allocated to restricted shares Undistributed Earnings (Loss) Allocated to Participating Securities, Basic, Total Undistributed Earnings (Loss) Allocated to Participating Securities, Basic Performance Bonds [Member] Debt Securities Payable [Member] 2023 Lessee, Operating Lease, Liability, to be Paid, Year One Actuarial gains, net amount Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax Local Phone Number Amount of lessee's undiscounted obligation for lease payment for operating lease due after fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). Lessee Operating Lease Liability Payments Due After Year Four Thereafter Impairment of Intangible Assets (Excluding Goodwill), Total Impairment of Intangible Assets (Excluding Goodwill) Underlying Asset Class [Domain] Schedule of Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Vesting period Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period Debt Disclosure [Abstract] Net Income (Loss) Attributable to Noncontrolling Interest, Total Net earnings attributable to noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest Net (earnings) loss attributable to noncontrolling interests Net earnings attributable to noncontrolling interests Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Disaggregation of Revenue [Table Text Block] Revenues by Major Source Shares available for grant (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross Other Liabilities, Noncurrent, Total Other long-term liabilities Treasury stock purchases Treasury Stock, Value, Acquired, Cost Method Long-term Debt, Total Long-Term Debt Term loan Beginning balance (in shares) Ending balance (in shares) Shares, Outstanding Line of Credit Facility, Remaining Borrowing Capacity Available borrowing capacity Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Inventory Disclosure [Abstract] Share-Based Payment Arrangement, Amount Capitalized Amortization of share-based compensation Total other comprehensive income, gross amount Other Comprehensive Income (Loss), before Tax Debt Instrument, Name [Domain] Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures, Total Investment in affiliates Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures Document Fiscal Year Focus Proceeds from Sale of Productive Assets, Total Proceeds from Sale of Productive Assets Proceeds from disposition of assets 2024 Lessee, Operating Lease, Liability, to be Paid, Year Two, Total Lessee, Operating Lease, Liability, to be Paid, Year Two Basic (in dollars per share) Earnings Per Share, Basic, Total Basic Goodwill, Gross Ending balance Balance Balance ASSETS Assets [Abstract] Increase (Decrease) in Operating Capital, Total Increase (decrease) in cash flows resulting from changes in operating assets and liabilities, net Increase (Decrease) in Operating Capital Prepaid expense and other current assets Guaranties [Abstract] Guarantees [Abstract] Treasury stock - at cost, 5.5 million shares at June 30, 2022 and 5.4 million at December 31, 2021 Treasury Stock, Value, Ending Balance Treasury Stock, Value, Beginning Balance Treasury Stock, Value, Total Treasury Stock, Value Debt Instrument, Face Amount Long term debt, face amount Long-Lived Tangible Asset [Axis] Schedule of Restructuring and Related Costs [Table] LIABILITIES AND STOCKHOLDERS' EQUITY Liabilities and Equity [Abstract] Impairment of Intangible Assets, Finite-Lived Income taxes refunded, net Income Taxes Paid, Net, Total Income taxes refunded Income Taxes Paid, Net Income Tax Authority [Axis] Net earnings Net earnings Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net loss Assets, Current [Abstract] Taxes, Miscellaneous, Total Taxes, other than on income Taxes, Miscellaneous unpaid balance unpaid balance Segment Data Segment Reporting Disclosure [Text Block] Changes in Other Comprehensive Income Schedule of Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block] Commitment Amount Line of Credit Facility, Commitment Fee Amount Summary of Changes in Goodwill Schedule of Goodwill [Table Text Block] Fair Value Hierarchy and NAV [Domain] Guarantor Obligations, Nature [Domain] Lease, Cost [Abstract] Pension contributions Defined Benefit Plan, Plan Assets, Contributions by Employer Cover [Abstract] Product and Service [Domain] Inventory, Finished Goods, Gross, Total Inventory, Finished Goods, Gross Goodwill impairment charge Goodwill, Impairment Loss Impairment Details of inventories [Abstract] Inventory, Net [Abstract] Current liabilities: Maximum [Member] Maximum [Member] Net Periodic Benefit Cost Schedule of Defined Benefit Plans Disclosures [Table Text Block] The age of eligible participants of the employee pension plan who will be grandfathered and not be impacted by the amendment to the pension plan. Employee Pension Plan, Grandfathered Participants, Participant Age Age of plan participants not impacted by pension plan amendment Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Amortization of net actuarial loss, income tax provision Amount of tax (expense) benefit of reclassification adjustment from accumulated other comprehensive (income) loss for prior service cost (credit) and settlement of defined benefit plan. Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Settlement, Reclassification Adjustment from AOCI, Tax Stock option exercises (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Details of Inventories Schedule of Inventory, Current [Table Text Block] Fair Value, Inputs, Level 3 [Member] Level 3 [Member] Compensation Cost Breakdown in Statement of Earnings Share-Based Payment Arrangement, Cost by Plan [Table Text Block] Three point five one series b notes due january nineteen two thousand thirty three. Three point Five One Series B Notes Due January Nineteen Two Thousand Thirty Three [Member] Variable interest rates Debt Instrument, Basis Spread on Variable Rate A table disclosing the information about earnings (loss) before taxes on income. Income Tax Disclosure [Table] Stock option exercises Stock Issued During Period, Value, Stock Options Exercised Asset Impairment Charges [Abstract] Foreign [Member] Foreign Tax Authority [Member] Long-Term Debt, Gross Carrying value Common Stock, Shares Authorized Common stock, shares authorized (in shares) Trading Symbol Earnings available to Kirby common stockholders - diluted Loss attributable to Kirby common stockholders - diluted Net Income (Loss) Available to Common Stockholders, Diluted Estimated percentage of costs related to service costs and other non-lease components. Percentage of Costs related to Service Costs Estimated Percentage of costs relate to service costs for leased towing vessels Selling, General and Administrative Expense, Total Selling, general and administrative Subsequent Event Type [Axis] Comprehensive income attributable to Kirby Comprehensive Income (Loss), Net of Tax, Attributable to Parent Accounts Payable, Current, Total Accounts payable Accounts Payable, Current Plan Name [Axis] Treasury stock purchases (in shares) Treasury stock purchases, (in shares) Treasury Stock, Shares, Acquired Debt Instrument, Periodic Payment, Interest Periodic payment, interest Long-Lived Tangible Asset [Domain] Return of investment to noncontrolling interests Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Common Stock, Par or Stated Value Per Share Common stock, par value per share (in dollars per share) Gain on disposition of assets Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property Gain on disposition of assets Variable Lease, Cost Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Defined Benefit Plan Disclosure [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Expected timing of satisfaction, period Long-Term Debt Long-Term Debt [Text Block] Debt Instrument [Line Items] Long-Term Debt, Type [Domain] Antidilutive securities excluded from computation of earnings per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets