ACCOUNTING POLICIES - Property (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2019	Dec. 31, 2020
Property, Plant and Equipment
Long-lived assets impairment		$ 6.5
ArcBest
Property, Plant and Equipment
Long-lived assets impairment		$ 6.5
Held-for-sale | Other long-term assets
Property, Plant and Equipment
Assets held for sale which are reported within other noncurrent assets	$ 0.6		$ 1.1
Structures | Minimum
Property, Plant and Equipment
Depreciation/amortization period	15 years
Structures | Maximum
Property, Plant and Equipment
Depreciation/amortization period	60 years
Revenue equipment | Minimum
Property, Plant and Equipment
Depreciation/amortization period	3 years
Revenue equipment | Maximum
Property, Plant and Equipment
Depreciation/amortization period	16 years
Service, office, and other equipment | Minimum
Property, Plant and Equipment
Depreciation/amortization period	2 years
Service, office, and other equipment | Maximum
Property, Plant and Equipment
Depreciation/amortization period	15 years
Software | Minimum
Property, Plant and Equipment
Depreciation/amortization period	2 years
Software | Maximum
Property, Plant and Equipment
Depreciation/amortization period	7 years