v3.26.1
Fair Value of Plan Assets (Details) - ArcBest 401(k) and DC Retirement Plan - USD ($)
12 Months Ended
Dec. 31, 2024
Dec. 31, 2025
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value $ 758,591,320 $ 866,052,351
Transfers into level 3 0  
Transfers out of level 3 0  
Mutual funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 420,500,038 113,457,844
Self-directed brokerage accounts    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 9,889,909 9,977,806
Collective trust funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 323,287,158 739,116,525
Recurring    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 758,591,320 866,052,351
EBP, Liability 0 0
Nonrecurring    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 0 0
EBP, Liability 0 0
Fair value hierarchy | Recurring    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 435,304,162 126,935,826
Fair value hierarchy | Recurring | Mutual funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 420,500,038 113,457,844
Fair value hierarchy | Recurring | Self-directed brokerage accounts    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 9,889,909 9,977,806
Fair value hierarchy | Recurring | ArcBest Corporation stock fund - common stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 4,914,215 3,412,517
Fair value hierarchy | Recurring | ArcBest Corporation stock fund - money market fund    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value   87,659
Level 1 | Recurring    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 430,389,947 126,935,826
Level 1 | Recurring | Mutual funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 420,500,038 113,457,844
Level 1 | Recurring | Self-directed brokerage accounts    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 9,889,909 9,977,806
Level 1 | Recurring | ArcBest Corporation stock fund - common stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value   3,412,517
Level 1 | Recurring | ArcBest Corporation stock fund - money market fund    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value   87,659
Level 2 | Recurring    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 4,914,215  
Level 2 | Recurring | ArcBest Corporation stock fund - common stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 4,914,215  
Level 3    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value 0 0
Net asset value | Recurring | Collective trust funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Investments at fair value $ 323,287,158 $ 739,116,525