STOCKHOLDERS' EQUITY - AOCI Components (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Jun. 30, 2025	Dec. 31, 2024	Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2023
Accumulated Other Comprehensive Income
Total after-tax amount	$ 1,322,918	$ 1,300,426	$ 1,314,362	$ 1,307,096	$ 1,231,538	$ 1,242,363
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income
Total pre-tax amount	139		337
Total after-tax amount	104	$ 452	272	2,346	$ 2,473	4,324
Unrecognized Net Periodic Benefit Credit
Accumulated Other Comprehensive Income
Total pre-tax amount	5,029		5,660
Total after-tax amount	3,734		4,203	4,504		5,061
Foreign Currency Translation
Accumulated Other Comprehensive Income
Total pre-tax amount	(4,890)		(5,323)
Total after-tax amount	$ (3,630)		$ (3,931)	$ (2,319)		$ (2,000)

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details

- Definition

Amount of equity (deficit) attributable to parent. Excludes temporary equity and equity attributable to noncontrolling interest.

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ARCBEST CORP /DE/ 10-Q