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liabilities and claims accrual Increase (Decrease) in Accrued Liabilities and Other Liabilities Increase (Decrease) in Accrued Liabilities and Other Liabilities Business Combination, Contingent Consideration, Type [Domain] Business Combination, Contingent Consideration, Type [Domain] Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Purchases of property and equipment Payments to Acquire Machinery and Equipment Share Repurchase Program [Axis] Share Repurchase Program [Axis] Class of Stock [Domain] Class of Stock [Domain] Transfers from property and equipment to assets held for sale [Member] Transfers from property and equipment to assets held for sale [Member] Transfers from property and equipment to assets held for sale [Member] Interest Interest Paid, Excluding Capitalized Interest, Operating Activity Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Number of operational tractors in fleet Number of Tractors In Fleet Number of Tractors In Fleet Assets, Fair Value Disclosure Assets, Fair Value Disclosure Property and equipment obtained in exchange for debt and finance lease liabilities from operating lease liabilities Property and equipment obtained in exchange for finance lease liabilities from operating lease liabilities [Member] Property and equipment obtained in exchange for finance lease liabilities from operating lease liabilities Defined Benefit Plan, Benefit Obligation, Payment for Settlement Defined Benefit Plan, Benefit Obligation, Payment for Settlement Minimum principal payment — frequency 3 Debt Instrument, Frequency of Periodic Payment Income Tax Authority [Axis] Income Tax Jurisdiction [Axis] Income Taxes Income Tax Disclosure [Text Block] Accounts payable Accounts Payable, Current Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Investment in noncontrolling interest Noncontrolling Interest, Increase from Business Combination Other adjustments to reconcile net income to net cash provided by operating activities Other Noncash Income (Expense) Purchase Commitments Commitments Disclosure [Text Block] Debt Instrument [Line Items] Debt Instrument [Line Items] Operating taxes and licenses Cost, Direct Tax and License Additional Paid-in Capital [Member] Additional Paid-in Capital [Member] Entity Filer Category Entity Filer Category Supplemental Cash Flow Elements [Abstract] Logistics [Member] Logistics [Member] Logistics [Member] Equipment [Member] Equipment [Member] Goodwill, Impairment Loss Goodwill, Impairment Loss U.S. Xpress U.S. Xpress [Member] U.S. Xpress Cash and cash equivalents Cash and Cash Equivalent Discount Rate (Period of Time) Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate Debt Instrument, Interest Rate During Period Debt Instrument, Interest Rate During Period Rental expense Operating Lease, Expense Gain on equity securities Debt and Equity Securities, Gain (Loss) Depreciation and amortization of property, equipment, and intangibles Depreciation, Depletion and Amortization Common stock issued to employees (Shares) Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture Schedule of Stock by Class [Table] Stock, Class of Stock [Table] Net income Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Property and equipment obtained in exchange for finance lease liabilities Right-of-Use Asset Obtained in Exchange for Finance Lease Liability Current assets: Assets, Current [Abstract] Entity Address, Address Line One Entity Address, Address Line One Income tax expense Income Tax Expense (Benefit) Convertible Senior Notes ConvertibleSeniorNotesDisclosureTextBlock [Text Block] ConvertibleSeniorNotesDisclosureTextBlock New Accounting Pronouncement or change in Accounting Principle, Description New Accounting Pronouncement or Change in Accounting Principle, Description Right-of-use assets obtained in exchange for operating lease liabilities Right Of Use Asset (Forfeited) Obtained In Exchange For Operating Lease Liability Right Of Use Asset (Forfeited) Obtained In Exchange For Operating Lease Liability Net increase (decrease) in cash, restricted cash, and equivalents Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Accounts Receivable Securitization Transfers and Servicing of Financial Assets [Text Block] Recently Issued Accounting Pronouncements Accounting Standards Update and Change in Accounting Principle [Text Block] Fuel Fuel Costs Net income attributable to Knight-Swift Net income Net Income (Loss) Attributable to Parent Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Proceeds from sale of property and equipment, including assets held for sale Proceeds from Sale of Property, Plant, and Equipment Statement [Table] Statement [Table] Unobservable Measurement Input, Uncertainty, Description Unobservable Measurement Input, Uncertainty, Description Interest income Investment Income, Interest LTL LTL [Member] LTL [Member] Less: cash received from receivables sold Transfer of Financial Assets Accounted for as Sales, Cash Proceeds Received for Assets Derecognized, Amount Debt Instrument, Convertible, Threshold Consecutive Trading Days Debt Instrument, Convertible, Threshold Consecutive Trading Days December 28 2024 Agreement December 28 2024 Agreement [Member] December 28 2024 Agreement Share-Based Payment Arrangement Share-Based Payment Arrangement [Member] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Revenue: Revenues [Abstract] Category of Item Purchased [Axis] Category of Item Purchased [Axis]