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Three point Four Six Series A Notes Due January Nineteen Two Thousand Thirty Three [Member] Revenues Revenue from Contract with Customer, Excluding Assessed Tax, Total Revenue from Contract with Customer, Excluding Assessed Tax Revenues by major source Marine Transportation (KMT) [Member] 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] Income Tax Description Abstract Income Tax Description [Abstract] Income Taxes [Abstract] Disaggregation of Revenue [Table Text Block] Revenues by Major Source Amy D. Husted Amy D. Husted [Member] Amy D. Husted. Contract with Customer, Liability, Current Deferred revenues Compensation Cost Breakdown in Statement of Earnings Share-Based Payment Arrangement, Cost by Plan [Table Text Block] Subsequent Events [Text Block] Subsequent Event Other income Other Nonoperating Income 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] Operating lease liabilities - less current portion Shares Outstanding Abstract Shares Outstanding [Abstract] Shares outstanding [Abstract] Net loss attributable to noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest, Total Net Income (Loss) Attributable to Noncontrolling Interest Net (earnings) loss attributable to noncontrolling interests Net earnings attributable to noncontrolling interests Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Debt Instrument, Unamortized Discount, Total Unamortized debt discounts and issuance costs Debt Instrument, Unamortized Discount Total current assets Assets, Current Total liabilities and equity Liabilities and Equity Entity Address, State or Province Long-Term Debt Long-Term Debt [Text Block] Director Plan [Member] Director Plan [Member] Represents to director plan of the equity-based compensation arrangement plan. Comprehensive income attributable to Kirby Comprehensive Income (Loss), Net of Tax, Attributable to Parent Inventories Inventory Disclosure [Text Block] Trading Symbol Common Stock, Shares, Issued, Total Common Stock, Shares, Issued Common stock, shares issued (in shares) Prepaid expense and other current assets Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Net Income (Loss) Attributable to Parent [Abstract] Net Income (Loss) Attributable to Parent [Abstract] Total capacity barrels. Total Capacity Barrels Total capacity of barrels Schedule of Long-Term Debt Instruments [Table] Foreign [Member] Foreign Tax Authority [Member] Beginning balance (in shares) Ending balance (in shares) Shares, Outstanding Line of Credit Facility, Remaining Borrowing Capacity Available borrowing capacity 2027 Lessee, Operating Lease, Liability, to be Paid, Year Three High Horsepower Towboats [Member] High Horsepower Towboats [Member] High horsepower towboats. AOCI Attributable to Parent [Member] Accumulated Other Comprehensive Income, Net [Member] Business Combination Disclosure [Text Block] Acquisitions Total other comprehensive income (loss), net of taxes Other Comprehensive Income (Loss), Net of Tax Entity Address, City or Town Operating Lease, Weighted Average Discount Rate, Percent Weighted average discount rate Refers to the entity that is being acquired or purchased in a merger or acquisition. Higman Marine, Inc [Member] Higman [Member] Other Comprehensive Income Other Comprehensive Income, Noncontrolling Interest [Text Block] Subsequent Event [Member] Subsequent Event [Member] Subsequent Event Type [Axis] Additional Paid-in Capital [Member] Additional Paid-in Capital [Member] Current liabilities: Assets, Current [Abstract] Current assets: Statement of Stockholders' Equity [Abstract] Operating Lease, Liability, Current Current portion of operating lease liabilities 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. 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Miller Statement of Comprehensive Income [Abstract] Scenario [Domain] Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Treasury stock, shares Treasury Stock, Common, Shares Entity Central Index Key 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 Plan Name [Domain] Earnings (loss) before taxes on income [Abstract] 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 Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Expected timing of satisfaction, period Foreign - current Current Foreign Tax Expense (Benefit) Represents to employee plan of the equity-based compensation arrangement plan. Employee Plan [Member] Employee Stock Award Plan [Member] Total current liabilities Liabilities, Current Entity Tax Identification Number Earnings (loss) before taxes on income Earnings before taxes on income Loss before taxes on income Loss before taxes on income Segment profit Payments of Debt Issuance Costs Payment of debt issuance costs Lessee, Operating Leases [Text Block] Leases Restricted Stock [Member] Restricted Stock [Member] Plan Name [Axis] Total assets Total assets Assets Operating lease right-of-use assets Entity Registrant Name Notes Payable to Bank, Current Bank notes payable Retained Earnings (Accumulated Deficit), Ending Balance Retained Earnings (Accumulated Deficit), Beginning Balance Retained Earnings (Accumulated Deficit), Total Retained earnings 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 Amortization of net actuarial gain, net 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 Amortization of net actuarial gain, gross amount Supplemental disclosures of cash flow information: Supplemental Cash Flow Information [Abstract] Income tax benefit Share-Based Payment Arrangement, Expense, Tax Benefit 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 Retained Earnings [Member] Retained Earnings [Member] Ending balance Beginning balance Total equity Equity, Including Portion Attributable to Noncontrolling Interest Deferred Income Tax Liabilities, Net, Total Deferred income taxes Deferred Income Tax Liabilities, Net Proceeds from Stock Options Exercised Proceeds from exercise of stock options Operating Lease, Liability, Total Operating lease liabilities Operating Lease, Liability Scenario Forecast [Member] Forecast [Member] Income taxes payable Accrued Income Taxes, Current Disaggregation of Revenue [Abstract] Equity Component [Domain] Segments [Axis] Pension contributions Defined Benefit Plan, Plan Assets, Contributions by Employer State and local: State and Local Income Tax Expense (Benefit), Continuing Operations [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] Sublease income Sublease income Sublease Income Debt Disclosure [Abstract] Earnings available to Kirby common stockholders - diluted Loss attributable to Kirby common stockholders - diluted Net Income (Loss) Available to Common Stockholders, Diluted Tax withholdings on equity award vesting Share-Based Payment Arrangement, Decrease for Tax Withholding Obligation Variable interest rates Debt Instrument, Basis Spread on Variable Rate Entity Current Reporting Status Other Proceeds from (Payments for) Other Financing Activities Common Stock, Shares Authorized Common stock, shares authorized (in shares) ASSETS Assets [Abstract] Base Rate [Member] Base Rate [Member] 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 Repayments of Long-term Debt, Total Payments on long-term debt Repayments of Long-Term Debt Payments on long-term debt Other Noncash Income (Expense), Total Other Other Noncash Income (Expense) Contract with Customer, Liability, Revenue Recognized Revenue recognized Accrued Liabilities, Current, Total Accrued liabilities Accrued Liabilities, Current Current Fiscal Year End Date Share-based Payment Arrangement, Noncash Expense, Total Share-Based Payment Arrangement, Noncash Expense Amortization of share-based compensation Operating income Operating Income (Loss) Operating loss Provision for deferred income taxes Deferred Income Tax Expense (Benefit), Total Deferred Income Tax Expense (Benefit) Total provision for taxes on income Provision for taxes on income Provision for taxes on income Income Tax Expense (Benefit) Borrowings and Payments Under the Bank Credit Facilities Schedule of Line of Credit Facilities [Table Text Block] Compensation cost Share-Based Payment Arrangement, Expense Payments related to tax withholding for share-based compensation Payment, Tax Withholding, Share-Based Payment Arrangement Disaggregation of Revenue [Table] Finite-Lived Intangible Assets, Net, Ending Balance Finite-Lived Intangible Assets, Net, Beginning Balance Finite-Lived Intangible Assets, Net, Total Other intangibles, net Weighted average common stock issued and outstanding (in shares) 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 Segment Reporting Information, by Segment Schedule of Segment Reporting Information, by Segment [Table Text Block] Revenues Revenue from Contract with Customer [Text Block] Debt Instrument, Face Amount Long term debt, face amount Gearbox repair Gearbox Repair [Member] Term Loan Due July 29, 2027 [Member] Term Loan Due July 29, 2027 [Member] Term Loan Due July Twenty Nine Two Thousand Twenty Seven [Member] Federal: Federal Income Tax Expense (Benefit), Continuing Operations [Abstract] Lessee, Operating Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract] Future Minimum Lease Payments Under Operating Leases [Abstract] Provision For Taxes On Income Abstract Provision for taxes on income [Abstract] Provision for taxes on income [Abstract] Refers to coastal transportation of refined petroleum products and black oil. Coastal Transportation [Member] Coastal Transportation [Member] Long-Term Debt, Type [Domain] Subsequent Events [Abstract] Commitments and Contingencies Disclosure [Abstract] Other Assets, Noncurrent, Total Other assets Other Assets, Noncurrent Operating Leases Weighted Average Discount Rate and Remaining Lease Term 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] Intersegment Eliminations [Member] Interest Paid, Excluding Capitalized Interest, Operating Activities Interest paid Interest paid Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Non-Rule 10b5-1 Arrangement Modified Non Rule10b51 Arr Modified [Flag] Non rule10b51 arrangement modified. Retirement Plan Type [Domain] Details of inventories [Abstract] Inventory, Net [Abstract] Raj Kumar. Raj Kumar [Member] Raj Kumar Kirby stockholders' equity: Kirby stockholders' equity: Lease, Cost [Table Text Block] Lease Cost Interest cost Defined Benefit Plan, Interest Cost Refers to a bank note payable. Bank Note Payable [Member] Bank Note Payable [Member] Other Postretirement Benefits [Member] Other Postretirement Benefits Plan [Member] Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Guaranties [Abstract] Guarantees [Abstract] Senior Notes Series B Due February 27, 2023 [Member] 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] Earnings Per Share [Abstract] Net earnings per share attributable to Kirby common stockholders: Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block] Future Minimum Lease Payments under Operating Leases Equipment Purchase Agreement [Member] Equipment Purchase Agreement [Member] Equipment purchase agreement. Segments [Domain] Scenario [Axis] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Underlying Asset Class [Domain] Revolving Credit Facility [Member] Schedule of Guarantor Obligations [Table] Basic Earnings Per Share, Basic, Total Basic Contingencies and commitments Commitments and Contingencies Inland Tank Barges [Member] Inland Tank Barges Inland Tank Barges [Member] Number of horsepower towboats Number of Horsepower Towboats Number of horsepower towboats. Business Combinations [Abstract] Income Statement [Abstract] Defined Benefit Plan, Amortization of Gain (Loss) Amortization of actuarial (gain) loss 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 Operating lease cost Operating Lease, Cost Short-term lease cost Short-Term Lease, Cost Guarantor Obligations [Line Items] Retirement Benefits [Abstract] Statistical Measurement [Domain] Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Document Period End Date Statistical Measurement [Axis] Contingencies and Commitments Commitments and Contingencies Disclosure [Text Block] Refers to amount of general corporate expenses. General corporate expenses General corporate expenses Operating Lease, Payments Operating cash outflow from operating leases Operating cash outflow from operating leases Diluted Earnings Per Share, Diluted, Total Diluted Product and Service [Domain] Lease, Cost [Abstract] Foreign currency translation, income tax (provision) benefit Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax, Total Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax 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 Revenue from Contract with Customer [Abstract] Performance Bonds [Member] Debt Securities Payable [Member] Debt Instrument, Name [Domain] Cash paid during the period: Cash Paid During Period Abstract Cash paid during the period [Abstract] Number of reportable segments Number of Reportable Segments Additional Paid in Capital, Common Stock, Ending Balance Additional Paid in Capital, Common Stock, Beginning Balance Additional Paid in Capital Additional paid-in capital Pension Benefits [Member] Pension Plan [Member] Retirement Plans [Abstract] Defined Benefit Plan, Additional Information [Abstract] 3.51% senior notes due January 19, 2033 [Member] Three Point Five One Percentage Senior Notes Due January Nineteen Two Thousand Thirty Three [Member] Three Point Five One Percentage Senior Notes Due January Nineteen Two Thousand Thirty Three [Member] Treasury stock purchases Treasury stock purchases Payments for Repurchase of Common Stock 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 Decrease in cash flows resulting from changes in operating assets and liabilities, net Increase (Decrease) in Operating Capital, Total Increase (Decrease) in Operating Capital Schedule of Restructuring and Related Costs [Table] 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 Proceeds from (Repayments of) Notes Payable Borrowings on long-term debt David W. Grzebinski. David W. Grzebinski [Member] David W. Grzebinski Stock option exercises (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period LIABILITIES AND STOCKHOLDERS' EQUITY Liabilities and Equity [Abstract] Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] Entity Address, Postal Zip Code Entity Interactive Data Current Power generation [Member] Power Generation [Member] Power generation. Credit Facility [Domain] Excise taxes on treasury stock purchases Excise taxes on treasury stock purchases Excise Taxes On Treasury Stock Purchases Excise taxes on treasury stock purchases Less: imputed interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Borrowings on bank credit facilities, net Borrowings (Payments) on bank credit facilities Proceeds from (Repayments of) Lines of Credit Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Rule 10b5-1 Trading Arrangement. Rule 10b5-1 Trading Arrangement [Member] Rule 10b5-1 Trading Arrangement Entity Incorporation, State or Country Code Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax [Abstract] Net earnings per share basic attributable to Kirby common stockholders: Earnings Per Share, Basic [Abstract] Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax [Abstract] Non Cash Investing Activity Abstract Non-cash investing activity: [Abstract] Non-cash investing activity: Equity Components [Axis] Other [Member] Other Segments [Member] Retirement Plans Retirement Benefits [Text Block] Specialty Barges [Member] Specialty Barges [Member] Specialty barges. Debt Instrument Carrying Value And Fair Value Abstract Debt Instrument, Carrying Value and Fair Value [Abstract] Carrying Value and Fair Value of Debt Outstanding [Abstract] Inventory Disclosure [Abstract] Payments to Acquire Businesses, Gross Cash paid for acquisition Number of tank barges. Number of Tank Barges Number of tank barges Local Phone Number Current Current Federal Tax Expense (Benefit) 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] 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 Goodwill, Ending Balance Goodwill, Beginning Balance Goodwill, Total Goodwill Goodwill Balance Statement of Cash Flows [Abstract] 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 Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Income Tax Authority [Domain] Organization, Consolidation and Presentation of Financial Statements [Abstract] Accumulated Other Comprehensive Income (Loss), Net of Tax, Total Accumulated other comprehensive income - net Accumulated Other Comprehensive Income (Loss), Net of Tax Segment Reporting Information [Line Items] Amortization of share-based compensation Share-Based Payment Arrangement, Amount Capitalized Amortization of share-based compensation 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 Common Stock, Par or Stated Value Per Share Common stock, par value per share (in dollars per share) Interest rate Debt Instrument, Interest Rate, Stated Percentage Long-Lived Tangible Asset [Axis] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Maximum [Member] Maximum [Member] 3.46% Senior Notes Due January 19, 2033 [Member] Senior Notes Due January Nineteen Two Thousand Thirty Three [Member] Senior notes due january nineteen two thousand thirty three. Net earnings per share diluted attributable to Kirby common stockholders: Earnings Per Share, Diluted [Abstract] Consolidation Items [Domain] 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] Increase (decrease) in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Service cost Defined Benefit Plan, Service Cost 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 Basis for Preparation of the Condensed Financial Statements Basis of Accounting [Text Block] 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 Reporting Segments [Member] Operating Segments [Member] Details of Inventories Schedule of Inventory, Current [Table Text Block] SERP [Member] Supplemental Employee Retirement Plan [Member] Segment Data Segment Reporting Disclosure [Text Block] City Area Code Changes in Other Comprehensive Income (loss) Schedule of Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block] Deferred Deferred State and Local Income Tax Expense (Benefit) Inventories - net Inventories - net Inventory, Net Cash flows from operating activities: Total other comprehensive income, gross amount Other Comprehensive Income (Loss), before Tax Consolidation Items [Axis] 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] 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 Weighted Average Number of Shares Outstanding, Basic (in Shares) Weighted Average Number of Shares Outstanding, Basic (in shares) Weighted Average Number of Shares Outstanding, Basic Issued guaranties Guarantor Obligations, Maximum Exposure, Undiscounted Inventory, Work in Process, Gross Cash flows from financing activities: Statement [Table] Document Fiscal Period Focus Total lease payments Lessee, Operating Lease, Liability, to be Paid Total long-term liabilities Liabilities, Noncurrent 2026 Lessee, Operating Lease, Liability, to be Paid, Year Two, Total Lessee, Operating Lease, Liability, to be Paid, Year Two Statement [Line Items] Details of "Other" total assets [Abstract] Other Assets [Abstract] Carrying Values and Fair Values of Debt Outstanding Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Debt Instrument, Fair Value Disclosure, Total Debt Instrument, Fair Value Disclosure Fair value Antidilutive securities excluded from computation of earnings per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Contract with Customer, Asset, after Allowance for Credit Loss, Total Contract with Customer, Asset, after Allowance for Credit Loss Contract assets Total lease cost Lease, Cost Subsequent Event [Line Items] Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority Tax refund amount Accounts Receivable, after Allowance for Credit Loss, Current, Total Trade - less allowance for doubtful accounts Accounts Receivable, after Allowance for Credit Loss, Current Common Stock [Member] Common Stock [Member] Debt Instrument [Line Items] Accounts receivable: Accounts Receivable, after Allowance for Credit Loss, Current [Abstract] 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 Undistributed earnings reallocated to restricted shares Undistributed earnings reallocated to restricted shares Undistributed Earnings Reallocated To Restricted Shares Undistributed Earnings Reallocated To Restricted Shares. Entity Common Stock, Shares Outstanding Asset acquisition expected expiration term Asset Acquisition Expected Expiration Term Asset acquisition expected expiration term. Inventory, Finished Goods, Gross, Total Inventory, Finished Goods, Gross Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Axis] Treasury stock - at cost, 7.2 million shares at March 31, 2024 and 6.8 million at December 31, 2023 Treasury Stock, Value, Ending Balance Treasury Stock, Value, Beginning Balance Treasury Stock, Value, Total Treasury Stock, Value Cover [Abstract] Selling, General and Administrative Expense, Total Selling, general and administrative Document Fiscal Year Focus Income taxes paid, net Income Taxes Paid, Net, Total Income taxes refunded Income Taxes Paid, Net Other Supplemental Information About Operating Leases Abstract Other Supplemental Information about Operating Leases [Abstract] Other Supplemental Information about Operating Leases [Abstract] Credit Line Due June 30, 2024 [Member] Credit Line Due June Thirty Two Thousand Twenty Four [Member] Credit line due june thirty two thousand twenty four. Segment Reporting [Abstract] Proceeds from Sale of Productive Assets, Total Proceeds from Sale of Productive Assets Proceeds from disposition of assets Proceeds from sale of assets Security Exchange Name United States [Member] Domestic Tax Authority [Member] New Accounting Pronouncements, Policy [Policy Text Block] 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 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 Current Current State and Local Tax Expense (Benefit) Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Right-of-use assets obtained in exchange for lease obligations Treasury stock purchases (in shares) Treasury stock purchases, (in shares) Treasury Stock, Shares, Acquired Business Acquisition, Acquiree [Domain] Total other comprehensive income, income tax (provision) benefit Total other comprehensive income, income tax (provision) benefit Other Comprehensive Income (Loss), Tax, Total Other Comprehensive Income (Loss), Tax Stock option exercises Stock Issued During Period, Value, Stock Options Exercised Entity Emerging Growth Company Amendment Flag Employee Stock Award Plan Abstract Employee Stock Award Plan [Abstract] Stock Award Plan Information [Abstract] Deferred Income Taxes and Other Tax Receivable, Current Income tax receivable 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] Leases [Abstract] Variable Rate [Domain] Securities Act File Number Credit facility, expiration date Line of Credit Facility, Expiration Date 2024 Lessee, Operating Lease, Liability, to be Paid, Remainder of Fiscal Year, Total Lessee, Operating Lease, Liability, to be Paid, Remainder of Fiscal Year Long-term Debt, Excluding Current Maturities, Total Long-term debt, net - less current portion Long-Term Debt, Excluding Current Maturities 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 other assets Other Assets Share-Based Payment Arrangement [Abstract] Accounts Payable, Current, Total Accounts payable Accounts Payable, Current Debt Instrument [Axis] Costs and Expenses Total costs and expenses Other Other Receivables 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 Entity Address, Address Line Two Schedule of Defined Benefit Plans Disclosures [Table] Entity Small Business Entity Shell Company Tax withholdings on equity award vesting (in shares) Share-Based Payment Arrangement, Shares Withheld for Tax Withholding Obligation Earnings Per Share Earnings Per Share [Text Block] Revenues: Entity Address, Address Line One Rule 10b5-1 Arrangement Modified Rule 10b51 Arr Modified [Flag] Rule 10b51 arrangement modified. 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 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 Subsequent Event Type [Domain] Variable lease cost Variable Lease, Cost Taxes, Miscellaneous, Total Taxes, other than on income Taxes, Miscellaneous Long-Term Debt, Type [Axis] Net earnings Net earnings Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net loss Long-Term Debt, Gross Carrying value Depreciation and amortization Depreciation, Depletion and Amortization, Total Depreciation and amortization Product and Service [Axis] Treasury stock purchases Treasury Stock, Value, Acquired, Cost Method Revenues [Abstract] Segment Reporting Information, Revenue for Reportable Segment [Abstract] Title of 12(b) Security Treasury Stock [Member] Treasury Stock, Common [Member] Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Long-term Line of Credit, Total Credit facility, amount outstanding Long-Term Line of Credit Long-Lived Tangible Asset [Domain] Subsequent Event [Table] Stock Award Plans Share-Based Payment Arrangement [Text Block] Retirement Plan Type [Axis] Document Type Line of Credit [Member] Line of Credit [Member] Line of credit facility, current borrowing capacity Line of Credit Facility, Current Borrowing Capacity Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Document Quarterly Report Earnings available to Kirby common stockholders - basic Loss attributable to Kirby common stockholders - basic Net Income (Loss) Available to Common Stockholders, Basic Unsecured Debt [Member] Net Cash Provided by (Used in) Financing Activities Net cash used in financing activities Entity Filer Category 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 Earnings (loss) Before Taxes Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block] Variable Rate [Axis] Underlying Asset Class [Axis] Oil and gas [Member] Oil and Gas [Member] 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 Nonoperating Income (Expense), Total Other income Nonoperating Income (Expense) 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 Amortization of net actuarial gain, income tax (provision) benefit Finite-Lived Intangible Asset, Useful Life Average age Stockholders' Equity Attributable to Parent, Ending Balance Stockholders' Equity Attributable to Parent, Beginning Balance Total Kirby stockholders' equity Equity, Attributable to Parent Scott P. Miller one. Scott P. Miller One [Member] Scott P. Miller Date Adopted 3/08/2023 3.51 Series B Notes Due January 19, 2023 [Member] 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] SOFR [Member] Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] Net earnings attributable to Kirby Net earnings attributable to Kirby Other comprehensive income (loss), net of taxes: Other comprehensive income (loss), net of taxes: Increase (Decrease) in Stockholders' Equity [Roll Forward] Interest expense Interest Expense, Total Interest expense Interest Expense Letters of Credit [Member] Standby Letters of Credit [Member] A table disclosing the information about earnings (loss) before taxes on income. Income Tax Disclosure [Table] Net Periodic Benefit Cost Schedule of Defined Benefit Plans Disclosures [Table Text Block] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Statement of Financial Position [Abstract] Weighted average common stock outstanding - diluted Weighted Average Number of Shares Outstanding, Diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Impairment of Long-Lived Assets to be Disposed of Non-cash pre-tax impairment charge Impairments Impairments Credit Facility [Axis] Deferred Deferred Federal Income Tax Expense (Benefit) Cash paid for acquisition Payments to Acquire Productive Assets, Total Capital expenditures Payments to Acquire Productive Assets 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 Operating Lease, Weighted Average Remaining Lease Term Weighted average remaining lease term Net periodic benefit cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Taxes on Income Weighted average unvested restricted stock (in shares) Weighted Average Number of Shares, Restricted Stock Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of Loss Per Share Disaggregation of Revenue [Line Items] Income Tax Authority [Axis] 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 Costs and expenses: Costs and Expenses [Abstract] Total comprehensive income, net of taxes Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Total comprehensive income, net of taxes Business Acquisition [Axis] Income Tax Disclosure [Abstract] 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