Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2021	Apr. 30, 2021
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	000-19969
Entity Registrant Name	ARCBEST CORPORATION
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	71-0673405
Entity Address, Address Line One	8401 McClure Drive
Entity Address, City or Town	Fort Smith
Entity Address, State or Province	AR
Entity Address, Postal Zip Code	72916
City Area Code	479
Local Phone Number	785-6000
Title of 12(b) Security	Common Stock
Trading Symbol	ARCB
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		25,385,513
Entity Central Index Key	0000894405
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false