Amount of pre-tax expenses associated with multiemployer pension fund withdrawal liability.

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Represents the percentage of the entity's contributions to multiemployer pension plans that are made to the specified plan.

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Amount of contributions made to multiemployer plan by employer related to pension fund withdrawal liability.

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Represents the threshold percentage of the entity's contributions to the plan relative to total contributions received by the plan, which was exceeded during the period, triggering disclosure of the plan year.

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No definition available.

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Represents the percentage of the entity's contributions to each individually insignificant multiemployer pension plan.

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The threshold funded percentage of plans, below which a higher maximum period for insolvency is used to determine "critical and declining" status.

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No definition available.

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The threshold ratio of inactive participants to active participants, above which a higher maximum period for insolvency is used to determine "critical and declining" status.

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No definition available.

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The maximum period within which a plan in "critical and declining" status is expected to become insolvent, unless additional criteria relating to ratio of inactive to active participants or funded percentage are applicable.

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The maximum period within which a plan in "critical and declining" status is expected to become insolvent, if additional criteria relating to ratio of inactive to active participants or funded percentage are applicable.

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The period of time over which monthly payments have to be made for withdrawal liability settlement for multiemployer plan, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Represents the number of multiemployer plans to which the reporting entity currently contributes.

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Amount of cash outflow for initial lumpsum payment of withdrawal liability from multiemployer plan.

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Increase (decrease) in employer's contractual contribution rate to multiemployer plan.

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EMPLOYEE BENEFIT PLANS - Multiemployer Plans (Details) - Asset-Based $ in Thousands						3 Months Ended		12 Months Ended
	Aug. 01, 2024	Jan. 31, 2024	Aug. 01, 2023	Jan. 31, 2023	Aug. 01, 2022	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Dec. 31, 2024 USD ($) plan	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Sep. 30, 2024	Sep. 30, 2023	Jan. 01, 2023	Jan. 01, 2022
Multiemployer Plans
Minimum funded percentage of plans in green zone								80.00%
New England Teamsters Pension Fund \| Maximum
Multiemployer Plans
Actuarially certified projected funded percentage of multiemployer pension plan											65.00%	65.00%
Pension Plans
Multiemployer Plans
Number of multiemployer plans to which ABF Freight currently contributes \| plan								25
Maximum funded percentage of plans in yellow zone								80.00%
Maximum funded percentage of plans in red zone								65.00%
Maximum projected time to insolvency for plans in "critical and declining" status								14 years
Maximum projected time to insolvency for plans in "critical and declining" status if additional criteria apply								19 years
Threshold ratio of inactive to active participants for greater insolvency period to determine "critical and declining" status								2
Threshold funded percentage for greater insolvency period to determine "critical and declining" status								80.00%
Percentage of contributions to the multiemployer pension plans that are in critical and declining status								4.00%
Percentage of contributions to the multiemployer pension plans that are in critical status								54.00%
Percentage of contributions to the multiemployer pension plans that are in endangered status								0.00%
Total multiemployer pension contributions paid								$ 157,892	$ 162,484	$ 154,558
Pension Plans \| Central States Pension Plan
Multiemployer Plans
Multiemployer pension contributions paid, individually significant								$ 75,004	$ 77,708	$ 75,306
Threshold percentage of the entity's contributions relative to total fund contributions, which was exceeded during the period									5.00%	5.00%
Percentage of contributions to multiemployer pension plan								50.00%	50.00%	50.00%
Actuarially certified projected funded percentage of multiemployer pension plan													98.50%	14.50%
Pension Plans \| Central States Pension Plan \| Minimum
Multiemployer Plans
Actuarially certified projected funded percentage of multiemployer pension plan													80.00%
Pension Plans \| Western Conference Of Teamsters Pension Plan
Multiemployer Plans
Multiemployer pension contributions paid, individually significant								$ 27,701	$ 29,540	$ 28,051
Threshold percentage of the entity's contributions relative to total fund contributions, which was exceeded during the period									5.00%	5.00%
Pension Plans \| Central Pennsylvania Teamsters Defined Benefit Plan
Multiemployer Plans
Multiemployer pension contributions paid, individually significant								15,261	$ 15,540	$ 14,421
Threshold percentage of the entity's contributions relative to total fund contributions, which was exceeded during the period									5.00%	5.00%
Pension Plans \| I. B. of T. Union Local No. 710 Pension Fund
Multiemployer Plans
Multiemployer pension contributions paid, individually significant								11,560	$ 10,676	$ 9,838
Threshold percentage of the entity's contributions relative to total fund contributions, which was exceeded during the period		5.00%		5.00%
Pension Plans \| New England Teamsters Pension Fund
Multiemployer Plans
Multiemployer pension contributions paid, individually significant								4,548	4,636	4,449
Contributions to multiemployer plans related to pension fund withdrawal liability								1,600	1,600	1,600
Multiemployer pension fund withdrawal liability charge (pre-tax)							$ 37,900
Initial lump sum payment of withdrawal liability						$ 15,100
Withdrawal liability monthly payments period (in years)						17 years
Pension Plans \| All other plans in the aggregate
Multiemployer Plans
Multiemployer pension contributions paid, individually insignificant								$ 23,818	24,384	22,493
Pension Plans \| Multiemployer pension plans receiving 1% to 2% ABF Freight's total multiemployer pension contributions \| Minimum
Multiemployer Plans
Percentage of contributions to each individually insignificant multiemployer pension plan								1.00%
Pension Plans \| Multiemployer pension plans receiving 1% to 2% ABF Freight's total multiemployer pension contributions \| Maximum
Multiemployer Plans
Percentage of contributions to each individually insignificant multiemployer pension plan								2.00%
Health And Welfare Plans
Multiemployer Plans
Number of multiemployer plans to which ABF Freight currently contributes \| plan								38
Total multiemployer pension contributions paid								$ 218,500	$ 215,600	$ 194,400
Percentage increase in contribution rate for time worked related to benefit costs	3.70%		5.40%		4.30%