ArcBest (ARCB) 10-Q 7 May 21 2021 Q1 Quarterly report Financial data

Document and Entity Information

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

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
CURRENT ASSETS
Cash and cash equivalents	$ 301,542	$ 303,954
Short-term investments	59,316	65,408
Accounts receivable, less allowances (2021 - $7,736; 2020 - $7,851)	344,242	320,870
Other accounts receivable, less allowances (2021 - $662; 2020 - $660)	13,766	14,343
Prepaid expenses	40,356	37,774
Prepaid and refundable income taxes	4,604	11,397
Other	4,893	4,422
TOTAL CURRENT ASSETS	768,719	758,168
PROPERTY, PLANT AND EQUIPMENT
Land and structures	344,282	342,178
Revenue equipment	914,140	916,760
Service, office, and other equipment	235,727	233,810
Software	169,004	163,193
Leasehold improvements	15,534	15,156
TOTAL PROPERTY, PLANT AND EQUIPMENT, Gross	1,678,687	1,671,097
Less allowances for depreciation and amortization	1,015,989	992,407
PROPERTY, PLANT AND EQUIPMENT, net	662,698	678,690
GOODWILL	88,320	88,320
INTANGIBLE ASSETS, net	54,028	54,981
OPERATING RIGHT-OF-USE ASSETS	111,412	115,195
DEFERRED INCOME TAXES	6,289	6,158
OTHER LONG-TERM ASSETS	76,549	77,496
TOTAL ASSETS	1,768,015	1,779,008
CURRENT LIABILITIES
Accounts payable	177,885	170,898
Income taxes payable		316
Accrued expenses	235,161	246,746
Current portion of long-term debt	66,064	67,105
Current portion of operating lease liabilities	21,632	21,482
TOTAL CURRENT LIABILITIES	500,742	506,547
LONG-TERM DEBT, less current portion	200,773	217,119
OPERATING LEASE LIABILITIES, less current portion	94,473	97,839
POSTRETIREMENT LIABILITIES, less current portion	18,518	18,555
OTHER LONG-TERM LIABILITIES	33,992	37,948
DEFERRED INCOME TAXES	67,608	72,407
STOCKHOLDERS' EQUITY
Common stock, $0.01 par value, authorized 70,000,000 shares; issued 2021: 29,057,374 shares, 2020: 29,045,309 shares	291	290
Additional paid-in capital	344,542	342,354
Retained earnings	617,256	595,932
Treasury stock, at cost, 2021: 3,671,861 shares; 2020: 3,656,938 shares	(112,174)	(111,173)
Accumulated other comprehensive income	1,994	1,190
TOTAL STOCKHOLDERS' EQUITY	851,909	828,593
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 1,768,015	$ 1,779,008

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
CONSOLIDATED BALANCE SHEETS
Accounts receivable, allowances (in dollars)	$ 7,736	$ 7,851
Other accounts receivable, allowances (in dollars)	$ 662	$ 660
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized shares	70,000,000	70,000,000
Common stock, issued shares	29,057,374	29,045,309
Treasury stock, at cost, shares	3,671,861	3,656,938

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CONSOLIDATED STATEMENTS OF OPERATIONS
REVENUES	$ 829,213	$ 701,399
OPERATING EXPENSES	797,022	693,580
OPERATING INCOME	32,191	7,819
OTHER INCOME (COSTS)
Interest and dividend income	392	1,375
Interest and other related financing costs	(2,428)	(2,947)
Other, net	1,192	(3,862)
TOTAL OTHER INCOME (COSTS)	(844)	(5,434)
INCOME BEFORE INCOME TAXES	31,347	2,385
INCOME TAX PROVISION	7,986	483
NET INCOME	$ 23,361	$ 1,902
EARNINGS PER COMMON SHARE
Basic	$ 0.92	$ 0.07
Diluted	$ 0.87	$ 0.07
AVERAGE COMMON SHARES OUTSTANDING
Basic	25,454,921	25,390,377
Diluted	26,930,402	26,246,800
CASH DIVIDENDS DECLARED PER COMMON SHARE	$ 0.08	$ 0.08

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
NET INCOME	$ 23,361	$ 1,902
Postretirement benefit plans:
Net actuarial loss, net of tax of: (2021 - $-; 2020 - $3)		(8)
Pension settlement expense, net of tax of: (2021 - $-; 2020 - $23)		66
Amortization of unrecognized net periodic benefit credit, net of tax of: (2021 - $35; 2020 - $37)
Net actuarial gain	(100)	(108)
Interest rate swap and foreign currency translation:
Change in unrealized gain (loss) on interest rate swap, net of tax of: (2021 - $204; 2020 - $352)	575	(997)
Change in foreign currency translation, net of tax of: (2021 - $118; 2020 - $502)	329	(1,420)
OTHER COMPREHENSIVE INCOME (LOSS), net of tax	804	(2,467)
TOTAL COMPREHENSIVE INCOME (LOSS)	$ 24,165	$ (565)

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net actuarial loss, tax (benefit)		$ (3)
Pension settlement expense, tax		23
Amortization of unrecognized net periodic benefit costs (credit), tax	$ (35)	(37)
Change in unrealized gain (loss) on interest rate swap, tax (benefit)	204	(352)
Change in foreign currency translation, tax expense (benefit)	$ 118	$ (502)

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Common StockCumulative Effect, Period of Adoption, Adjusted Balance	Common Stock	Additional Paid-In CapitalCumulative Effect, Period of Adoption, Adjusted Balance	Additional Paid-In Capital	Retained EarningsCumulative Effect, Period of Adoption, Adjustment	Retained EarningsCumulative Effect, Period of Adoption, Adjusted Balance	Retained Earnings	Treasury StockCumulative Effect, Period of Adoption, Adjusted Balance	Treasury Stock	Accumulated Other Comprehensive Income (Loss)Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated Other Comprehensive Income (Loss)	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjusted Balance	Total
Balances at Dec. 31, 2019	$ 288	$ 288	$ 333,943	$ 333,943	$ (198)	$ 532,989	$ 533,187	$ (104,578)	$ (104,578)	$ 203	$ 203	$ (198)	$ 762,845	$ 763,043
Balances (in shares) at Dec. 31, 2019	28,811	28,811						3,405	3,405
Increase (Decrease) in Stockholders' Equity
Net income							1,902							1,902
Other comprehensive income, net of tax											(2,467)			(2,467)
Issuance of common stock under share-based compensation plans (in shares)		6
Tax effect of share-based compensation plans				(60)										(60)
Share-based compensation expense				2,181										2,181
Purchase of treasury stock									$ (3,162)					(3,162)
Purchase of treasury stock (in shares)									150
Dividends declared on common stock							(2,033)							(2,033)
Balances at Mar. 31, 2020		$ 288		336,064			532,858		$ (107,740)		(2,264)			759,206
Balances (in shares) at Mar. 31, 2020		28,817							3,555
Balances at Dec. 31, 2020		$ 290		342,354			595,932		$ (111,173)		1,190			828,593
Balances (in shares) at Dec. 31, 2020		29,045							3,657
Increase (Decrease) in Stockholders' Equity
Net income							23,361							23,361
Other comprehensive income, net of tax											804			804
Issuance of common stock under share-based compensation plans		$ 1		(1)
Issuance of common stock under share-based compensation plans (in shares)		12
Tax effect of share-based compensation plans				(165)										(165)
Share-based compensation expense				2,354										2,354
Purchase of treasury stock									$ (1,001)					(1,001)
Purchase of treasury stock (in shares)									15
Dividends declared on common stock							(2,037)							(2,037)
Balances at Mar. 31, 2021		$ 291		$ 344,542			$ 617,256		$ (112,174)		$ 1,994			$ 851,909
Balances (in shares) at Mar. 31, 2021		29,057							3,672

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
OPERATING ACTIVITIES
Net income	$ 23,361	$ 1,902
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	29,387	28,032
Amortization of intangibles	967	981
Pension settlement expense		89
Share-based compensation expense	2,354	2,181
Provision for losses on accounts receivable	(96)	1,383
Change in deferred income taxes	(4,998)	(2,815)
Gain on sale of property and equipment	(8,635)	(2,130)
Changes in operating assets and liabilities:
Receivables	(22,568)	3,874
Prepaid expenses	(2,582)	(3,429)
Other assets	(164)	5,800
Income taxes	6,376	2,949
Operating right-of-use assets and lease liabilities, net	567	(138)
Accounts payable, accrued expenses, and other liabilities	(1,435)	(15,550)
NET CASH PROVIDED BY OPERATING ACTIVITIES	22,534	23,129
INVESTING ACTIVITIES
Purchases of property, plant and equipment, net of financings	(9,588)	(6,738)
Proceeds from sale of property and equipment	10,079	4,692
Purchases of short-term investments	(18,130)	(73,973)
Proceeds from sale of short-term investments	24,418	12,210
Capitalization of internally developed software	(5,705)	(3,342)
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES	1,074	(67,151)
FINANCING ACTIVITIES
Borrowings under credit facilities		180,000
Borrowings under accounts receivable securitization program		45,000
Payments on long-term debt	(17,387)	(14,598)
Net change in book overdrafts	(5,434)	(10,869)
Payment of common stock dividends	(2,037)	(2,033)
Purchases of treasury stock	(1,001)	(3,162)
Payments for tax withheld on share-based compensation	(161)	(60)
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	(26,020)	194,278
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(2,412)	150,256
Cash and cash equivalents at beginning of period	303,954	201,909
CASH AND CASH EQUIVALENTS CASH AT END OF PERIOD	301,542	352,165
NONCASH INVESTING ACTIVITIES
Accruals for equipment received	233	39
Lease liabilities arising from obtaining right-of-use assets	$ 1,959	$ 10,370

ORGANIZATION AND DESCRIPTION OF

ORGANIZATION AND DESCRIPTION OF THE BUSINESS AND FINANCIAL STATEMENT PRESENTATION	3 Months Ended
	Mar. 31, 2021
ORGANIZATION AND DESCRIPTION OF THE BUSINESS AND FINANCIAL STATEMENT PRESENTATION
ORGANIZATION AND DESCRIPTION OF THE BUSINESS AND FINANCIAL STATEMENT PRESENTATION	NOTE A – ORGANIZATIO N AND DESCRIPTION OF THE BUSINESS AND FINANCIAL STATEMENT PRESENTATION ​ ArcBest Corporation ™ ​ The Asset-Based segment represented approximately 64% of the Company’s total revenues before other revenues and intercompany eliminations for the three months ended March 31, 2021. As of March 2021, approximately 82% of the Asset-Based segment’s employees were covered under a collective bargaining agreement, the ABF National Master Freight Agreement (the “2018 ABF NMFA”), with the International Brotherhood of Teamsters (the “IBT”), which will remain in effect through June 30, 2023. ​ Financial Statement Presentation ​ The accompanying unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States and applicable rules and regulations of the Securities and Exchange Commission (the “SEC”) pertaining to interim financial information. Accordingly, these interim financial statements do not include all information or footnote disclosures required by accounting principles generally accepted in the United States for complete financial statements and, therefore, should be read in conjunction with the audited financial statements and accompanying notes included in the Company’s 2020 Annual Report on Form 10-K and other current filings with the SEC. In the opinion of management, all adjustments (which are of a normal and recurring nature) considered necessary for a fair presentation have been included. ​ The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual amounts may differ from those estimates. The Company considered the impact of the novel coronavirus (“COVID-19”) pandemic on the estimates and assumptions used in preparation of the Company’s consolidated financial statements as of and for the three months ended March 31, 2021. Given the uncertainties regarding the economic environment and the impact of the COVID-19 pandemic on our business, it is possible that these estimates and assumptions may materially change in future periods. ​ Reclassifications: ​ Adopted Accounting Pronouncements ​ ASC Topic 740, Income Taxes ​ Accounting Pronouncements Not Yet Adopted ​ Management believes there is no other new accounting guidance issued but not yet effective that is relevant to the Company’s current financial statements. ​

FINANCIAL INSTRUMENTS AND FAIR

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS	3 Months Ended
	Mar. 31, 2021
FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS
FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS	NOTE B – FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS ​ Financial Instruments ​ The following table presents the components of cash and cash equivalents and short-term investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31 December 31 ​ ​ 2021 ​ 2020 ​ ​ ​ (in thousands) ​ Cash and cash equivalents ​ ​ ​ ​ ​ ​ ​ Cash deposits (1) ​ $ 236,380 ​ $ 240,687 ​ Variable rate demand notes (1)(2) ​ 29,161 ​ 29,066 ​ Money market funds (3) ​ 36,001 ​ 34,201 ​ Total cash and cash equivalents ​ $ 301,542 ​ $ 303,954 ​ ​ ​ ​ ​ ​ ​ ​ ​ Short-term investments ​ ​ ​ ​ ​ ​ ​ Certificates of deposit (1) ​ $ 59,316 ​ $ 53,297 ​ U.S. Treasury securities (4) ​ ​ — ​ ​ 12,111 ​ Total short-term investments ​ $ 59,316 ​ $ 65,408 ​ ​ (1) Recorded at cost plus accrued interest, which approximates fair value. (2) Amounts may be redeemed on a daily basis with the original issuer. (3) Recorded at fair value as determined by quoted market prices (see amounts presented in the table of financial assets and liabilities measured at fair value within this Note). (4) Recorded at amortized cost plus accrued interest, which approximates fair value. U.S. Treasury securities included in short-term investments are held-to-maturity investments with maturity dates of less than one year. ​ The Company’s long-term financial instruments are presented in the table of financial assets and liabilities measured at fair value within this Note. ​ Concentrations of Credit Risk of Financial Instruments The Company is potentially subject to concentrations of credit risk related to its cash, cash equivalents, and short-term investments. The Company reduces credit risk by maintaining its cash deposits primarily in FDIC-insured accounts and placing its short-term investments primarily in FDIC-insured certificates of deposit. However, certain cash deposits and certificates of deposit may exceed federally insured limits. At March 31, 2021 and December 31, 2020, cash, cash equivalents, and short-term investments totaling $152.9 million and $156.4 million, respectively, were neither FDIC insured nor direct obligations of the U.S. government. ​ Fair Value Disclosure of Financial Instruments Fair value disclosures are made in accordance with the following hierarchy of valuation techniques based on whether the inputs of market data and market assumptions used to measure fair value are observable or unobservable: ​ ● Level 1 — Quoted prices for identical assets and liabilities in active markets. ● Level 2 — Quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets and liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data. ● Level 3 — Unobservable inputs (Company’s market assumptions) that are significant to the valuation model. ​ Fair value and carrying value disclosures of financial instruments are presented in the following table: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31 ​ December 31 ​ ​ 2021 2020 ​ ​ (in thousands) ​ ​ ​ ​ Carrying ​ Fair ​ Carrying ​ Fair ​ ​ ​ ​ Value ​ Value ​ Value ​ Value ​ Credit Facility (1) ​ $ 70,000 ​ $ 70,000 ​ $ 70,000 ​ $ 70,000 ​ Notes payable (2) ​ 196,830 ​ 201,282 ​ 214,216 ​ 217,226 ​ New England Pension Fund withdrawal liability (3) ​ ​ 21,250 ​ ​ 23,361 ​ ​ 21,407 ​ ​ 25,523 ​ ​ ​ $ 288,080 ​ $ 294,643 ​ $ 305,623 ​ $ 312,749 ​ ​ (1) The revolving credit facility (the “Credit Facility”) carries a variable interest rate based on LIBOR, plus a margin, that is considered to be priced at market for debt instruments having similar terms and collateral requirements (Level 2 of the fair value hierarchy). (2) Fair value of the notes payable was determined using a present value income approach based on quoted interest rates from lending institutions with which the Company would enter into similar transactions (Level 2 of the fair value hierarchy). (3) ABF Freight’s multiemployer pension plan obligation with the New England Teamsters and Trucking Industry Pension Fund (the “New England Pension Fund”) was restructured under a transition agreement effective on August 1, 2018, which resulted in a related withdrawal liability (see in Note I to the consolidated financial statements in Item 8 of the Company’s 2020 Annual Report on Form 10-K). The fair value of the outstanding withdrawal liability is equal to the present value of the future withdrawal liability payments, discounted at an interest rate of 3.4% and 2.6% at March 31, 2021 and December 31, 2020, respectively, determined using the 20-year U.S. Treasury rate plus a spread (Level 2 of the fair value hierarchy). Included in other long-term liabilities with the current portion included in accrued expenses. ​ Assets and Liabilities Measured at Fair Value on a Recurring Basis ​ The following table presents the assets and liabilities that are measured at fair value on a recurring basis: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2021 ​ ​ ​ ​ ​ ​ Fair Value Measurements Using ​ ​ ​ ​ ​ ​ Quoted Prices Significant Significant ​ ​ ​ ​ ​ In Active ​ Observable ​ Unobservable ​ ​ ​ ​ ​ ​ Markets ​ Inputs ​ Inputs ​ ​ ​ Total (Level 1) (Level 2) (Level 3) ​ ​ (in thousands) ​ Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds (1) ​ $ 36,001 ​ $ 36,001 ​ $ — ​ $ — ​ Equity, bond, and money market mutual funds held in trust related to the Voluntary Savings Plan (2) ​ 3,017 ​ 3,017 ​ — ​ — ​ Interest rate swaps (3) ​ ​ 351 ​ ​ — ​ ​ 351 ​ ​ — ​ ​ ​ $ 39,369 ​ $ 39,018 ​ $ 351 ​ $ — ​ Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swaps (3) ​ $ 1,194 ​ $ — ​ $ 1,194 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ ​ ​ ​ Fair Value Measurements Using ​ ​ ​ ​ ​ ​ Quoted Prices Significant Significant ​ ​ ​ ​ ​ In Active ​ Observable ​ Unobservable ​ ​ ​ ​ ​ ​ Markets ​ Inputs ​ Inputs ​ ​ ​ Total (Level 1) (Level 2) (Level 3) ​ ​ ​ (in thousands) ​ Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds (1) ​ $ 34,201 ​ $ 34,201 ​ $ — ​ $ — ​ Equity, bond, and money market mutual funds held in trust related to the Voluntary Savings Plan (2) ​ 2,955 ​ 2,955 ​ — ​ — ​ ​ ​ $ 37,156 ​ $ 37,156 ​ $ — ​ $ — ​ Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swaps (3) ​ $ 1,622 ​ $ — ​ $ 1,622 ​ $ — ​ ​ (1) Included in cash and cash equivalents. (2) Nonqualified deferred compensation plan investments consist of U.S. and international equity mutual funds, government and corporate bond mutual funds, and money market funds which are held in a trust with a third-party brokerage firm. Included in other long-term assets, with a corresponding liability reported within other long-term liabilities. (3) Included in other long-term assets or other long-term liabilities. The fair values of the interest rate swaps were determined by discounting future cash flows and receipts based on expected interest rates observed in market interest rate curves adjusted for estimated credit valuation considerations reflecting nonperformance risk of the Company and the counterparty, which are considered to be in Level 3 of the fair value hierarchy. The Company assessed Level 3 inputs as insignificant to the valuation at March 31, 2021 and December 31, 2020 and considers the interest rate swap valuations in Level 2 of the fair value hierarchy.

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS	3 Months Ended
	Mar. 31, 2021
GOODWILL AND INTANGIBLE ASSETS
GOODWILL AND INTANGIBLE ASSETS	NOTE C – GOODWILL AND INTANGIBLE ASSETS ​ Goodwill represents the excess of cost over the fair value of net identifiable tangible and intangible assets acquired. Goodwill by reportable operating segment consisted of $87.7 million and $0.6 million reported in the ArcBest and FleetNet segments, respectively, at both March 31, 2021 and December 31, 2020. ​ Intangible assets consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2021 ​ December 31, 2020 ​ ​ Weighted-Average ​ ​ ​ ​ Accumulated ​ Net ​ ​ ​ ​ Accumulated ​ Net ​ Amortization Period Cost Amortization Value ​ Cost Amortization Value ​ ​ (in years) ​ (in thousands) ​ (in thousands) Finite-lived intangible assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Customer relationships 14 ​ $ 52,721 ​ $ 31,429 ​ $ 21,292 ​ $ 52,721 ​ $ 30,477 ​ $ 22,244 ​ Other ​ 13 ​ ​ 994 ​ ​ 558 ​ ​ 436 ​ ​ 980 ​ ​ 543 ​ ​ 437 ​ ​ 14 ​ 53,715 ​ 31,987 ​ 21,728 ​ ​ 53,701 ​ 31,020 ​ 22,681 ​ Indefinite-lived intangible assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Trade name N/A ​ 32,300 ​ N/A ​ 32,300 ​ ​ 32,300 ​ N/A ​ 32,300 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total intangible assets N/A ​ $ 86,015 ​ $ 31,987 ​ $ 54,028 ​ $ 86,001 ​ $ 31,020 ​ $ 54,981 ​ ​ ​ The future amortization for intangible assets acquired through business acquisitions as of March 31, 2021 was as follows: ​ ​ ​ ​ ​ ​ ​ Amortization of ​ ​ Intangible Assets ​ ​ ​ (in thousands) ​ Remainder of 2021 ​ $ 2,870 ​ 2022 ​ 3,815 ​ 2023 ​ 3,722 ​ 2024 ​ 3,689 ​ 2025 ​ ​ 3,674 ​ Thereafter ​ ​ 3,958 ​ Total amortization ​ $ 21,728 ​ ​ ​

INCOME TAXES

INCOME TAXES	3 Months Ended
	Mar. 31, 2021
INCOME TAXES
INCOME TAXES	NOTE D – INCOME TAXES ​ The effective tax rate was 25.5% and 20.3% for the three months ended March 31, 2021 and 2020, respectively. State tax rates vary among states and average approximately 6.0% to 6.5%, although some state rates are higher and a small number of states do not impose an income tax. ​ For the three months ended March 31, 2021, the difference between the Company’s effective tax rate and the federal statutory rate primarily resulted from state income taxes, nondeductible expenses, changes in the cash surrender value of life insurance, federal research and development tax credits, changes in tax valuation allowances, and tax benefit from the vesting of stock awards. For the three months ended March 31, 2020, the difference between the Company’s effective tax rate and the federal statutory rate primarily resulted from state income taxes, nondeductible expenses, changes in the cash surrender value of life insurance, federal alternative fuel and research development tax credits, changes in valuation allowances, and the reversal of an uncertain tax position. ​ As of March 31, 2021, the Company’s deferred tax liabilities, which will reverse in future years, exceeded the deferred tax assets. The Company evaluated the total deferred tax assets at March 31, 2021 and concluded that, other than for certain deferred tax assets related to foreign and state tax credit carryforwards and federal and state net operating losses, the assets did not exceed the amount for which realization is more likely than not. In making this determination, the Company considered the future reversal of existing taxable temporary differences, future taxable income, and tax planning strategies. Valuation allowances for deferred tax assets totaled $1.4 million and $1.3 million at March 31, 2021 and December 31, 2020, respectively. ​ The Company had a reserve for uncertain tax positions of $0.9 million at December 31, 2020. The reserve was reversed in the first quarter of 2020 due to the expiration of the statute of limitations. At March 31, 2021, the Company has no reserve for uncertain tax positions. ​ The Company paid federal and state income taxes of $6.5 million during the three months ended March 31, 2021, and paid foreign and state income taxes of $0.3 million during the three months ended March 31, 2020, respectively. The Company received refunds of less than $0.1 million of federal and state income taxes and refunds of $0.4 million of federal income taxes that were paid in prior years during the three months ended March 31, 2021 and 2020, respectively.

LEASES

LEASES	3 Months Ended
	Mar. 31, 2021
LEASES
LEASES	NOTE E – LEASES ​ The Company leases, under finance and operating lease arrangements, certain facilities used primarily in the Asset-Based segment service center operations, certain revenue equipment used in the ArcBest segment operations, and certain other office equipment. ​ The components of operating lease expense were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, 2021 March 31, 2020 ​ ​ (in thousands) ​ Operating lease expense ​ $ 6,642 ​ $ 5,796 ​ Variable lease expense ​ ​ 1,332 ​ ​ 1,040 ​ Sublease income ​ ​ (155) ​ ​ (92) ​ ​ ​ ​ ​ ​ ​ ​ ​ Total operating lease expense (1) ​ $ 7,819 ​ $ 6,744 ​ (1) Operating lease expense excludes short-term leases with a term of 12 months or less. ​ The operating cash flows from operating lease activity were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31, 2021 ​ March 31, 2020 ​ ​ ​ (in thousands) ​ Noncash change in operating right-of-use assets ​ $ 5,741 ​ $ 5,815 ​ Change in operating lease liabilities ​ ​ (5,174) ​ ​ (5,953) ​ Operating right-of-use-assets and lease liabilities, net ​ $ 567 ​ $ (138) ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash paid for amounts included in the measurement of operating lease liabilities ​ $ (6,079) ​ $ (5,925) ​ ​ Maturities of operating lease liabilities at March 31, 2021 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Equipment ​ ​ ​ ​ ​ ​ Land and ​ and ​ ​ Total Structures Other ​ (in thousands) ​ Remainder of 2021 ​ $ 18,816 ​ $ 18,748 ​ $ 68 ​ 2022 ​ 21,459 ​ 21,423 ​ 36 ​ 2023 ​ 17,248 ​ 17,223 ​ 25 ​ 2024 ​ 15,088 ​ 15,088 ​ — ​ 2025 ​ 12,561 ​ 12,561 ​ — ​ Thereafter ​ 43,109 ​ 43,109 ​ — ​ Total lease payments ​ ​ 128,281 ​ ​ 128,152 ​ ​ 129 ​ Less imputed interest ​ ​ (12,176) ​ ​ (12,174) ​ ​ (2) ​ Total ​ $ 116,105 ​ $ 115,978 ​ $ 127 ​ ​

LONG-TERM DEBT AND FINANCING AR

LONG-TERM DEBT AND FINANCING ARRANGEMENTS	3 Months Ended
	Mar. 31, 2021
LONG-TERM DEBT AND FINANCING ARRANGEMENTS
LONG-TERM DEBT AND FINANCING ARRANGEMENTS	NOTE F – LONG-TERM DEBT AND FINANCING ARRANGEMENTS ​ Long-Term Debt Obligations ​ Long-term debt consisted of borrowings outstanding under the Company’s revolving credit facility which is further described in Financing Arrangements within this Note, and notes payable and finance lease obligations related to the financing of revenue equipment (tractors and trailers used primarily in Asset-Based segment operations), certain other equipment, and software as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31 ​ December 31 ​ ​ 2021 2020 ​ ​ (in thousands) ​ Credit Facility (interest rate of 1.2% (1) ​ $ 70,000 ​ $ 70,000 ​ Notes payable (weighted-average interest rate of 3.0% at March 31, 2021) ​ 196,830 ​ 214,216 ​ Finance lease obligations (weighted-average interest rate of 3.3% at March 31, 2021) ​ 7 ​ 8 ​ ​ ​ 266,837 ​ 284,224 ​ Less current portion ​ 66,064 ​ 67,105 ​ Long-term debt, less current portion ​ $ 200,773 ​ $ 217,119 ​ ​ (1) The interest rate swap mitigates interest rate risk by effectively converting $50.0 million of borrowings under the Credit Facility from variable-rate interest to fixed-rate interest with a per annum rate of 3.12% based on the margin of the Credit Facility as of both March 31, 2021 and December 31, 2020. ​ ​ Scheduled maturities of long-term debt obligations as of March 31, 2021 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Credit ​ Notes ​ Finance Lease ​ ​ Total Facility (1) Payable Obligations ​ ​ (in thousands) ​ Due in one year or less $ 71,839 $ 899 $ 70,933 ​ $ 7 ​ Due after one year through two years ​ 60,650 ​ 1,005 ​ 59,645 ​ — ​ Due after two years through three years ​ 43,891 ​ 1,362 ​ 42,529 ​ — ​ Due after three years through four years ​ 98,088 ​ 70,854 ​ 27,234 ​ — ​ Due after four years through five years ​ 6,117 ​ — ​ 6,117 ​ — ​ Due after five years ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ Total payments ​ 280,585 ​ 74,120 ​ 206,458 ​ 7 ​ Less amounts representing interest ​ 13,748 ​ 4,120 ​ 9,628 ​ — ​ Long-term debt $ 266,837 $ 70,000 $ 196,830 ​ $ 7 ​ ​ (1) The future interest payments included in the scheduled maturities due are calculated using variable interest rates based on the LIBOR swap curve, plus the anticipated applicable margin. ​ Assets securing notes payable or held under finance leases were included in property, plant and equipment as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31 ​ December 31 ​ ​ 2021 2020 ​ ​ (in thousands) Revenue equipment $ 325,562 $ 326,823 ​ Service, office, and other equipment ​ ​ 26,270 ​ ​ 26,270 ​ Total assets securing notes payable or held under finance leases ​ 351,832 ​ 353,093 ​ Less accumulated depreciation and amortization (1) ​ 126,398 ​ 115,424 ​ Net assets securing notes payable or held under finance leases ​ $ 225,434 ​ $ 237,669 ​ ​ ​ (1) Amortization of assets held under finance leases and depreciation of assets securing notes payable are included in depreciation expense. ​ Financing Arrangements ​ Credit Facility The Company has a revolving credit facility (the “Credit Facility”) under its Third Amended and Restated Credit Agreement (the “Credit Agreement”) with an initial maximum credit amount of $250.0 million, including a swing line facility in an aggregate amount of up to $25.0 million and a letter of credit sub-facility providing for the issuance of letters of credit up to an aggregate amount of $20.0 million. The Company may request additional revolving commitments or incremental term loans thereunder up to an aggregate amount of $125.0 million, subject to certain additional conditions as provided in the Credit Agreement. As of March 31, 2021, the Company had available borrowing capacity of $180.0 million under the initial maximum credit amount of the Credit Facility. ​ Principal payments under the Credit Facility are due upon maturity of the facility on October 1, 2024; however, borrowings may be repaid, at the Company’s discretion, in whole or in part at any time, without penalty, subject to required notice periods and compliance with minimum prepayment amounts. The Credit Agreement contains conditions, representations and warranties, events of default, and indemnification provisions that are customary for financings of this type, including, but not limited to, a minimum interest coverage ratio, a maximum adjusted leverage ratio, and limitations on incurrence of debt, investments, liens on assets, certain sale and leaseback transactions, transactions with affiliates, mergers, consolidations, purchases and sales of assets, and certain restricted payments. The Company was in compliance with the covenants under the Credit Agreement at March 31, 2021. ​ Interest Rate Swaps The Company has an interest rate swap agreement with a $50.0 million notional amount which started on January 2, 2020 and will mature on June 30, 2022. The Company receives floating-rate interest amounts based on one-month LIBOR in exchange for fixed-rate interest payments of 1.99% over the life of the agreement. The interest rate swap mitigates interest rate risk by effectively converting $50.0 million of borrowings under the Credit Facility from variable-rate interest to fixed-rate interest with a per annum rate of 3.12% based on the margin of the Credit Facility as of March 31, 2021. The fair value of the interest rate swap of $1.2 million and $1.4 million was recorded in other long-term liabilities in the consolidated balance sheet at March 31, 2021 and December 31, 2020, respectively. ​ The Company also has an interest rate swap agreement with a $50.0 million notional amount interest rate swap agreement which will start on June 30, 2022 and mature on October 1, 2024. The Company will receive floating-rate interest amounts based on one-month LIBOR in exchange for fixed-rate interest payments of 0.43% beginning on June 30, 2022 throughout the remaining term of the agreement. From June 30, 2022 to October 1, 2024, the extended interest rate swap agreement will effectively convert $50.0 million of borrowings under the Credit Facility from variable-rate interest to fixed-rate interest with a per annum rate of 1.56% based on the margin of the Credit Facility as of March 31, 2021. The fair value of the interest rate swap of $0.4 million was recorded in other long-term assets and $0.2 million was recorded in other long-term liabilities in the consolidated balance sheet at March 31, 2021 and December 31, 2020, respectively. ​ The unrealized gain or loss on the interest rate swap instruments was reported as a component of accumulated other comprehensive income, net of tax, in stockholders’ equity at March 31, 2021 and December 31, 2020, and the change in the unrealized loss on the interest rate swaps for the three months ended March 31, 2021 and 2020 was reported in other comprehensive income (loss), net of tax, in the consolidated statements of comprehensive income. The interest rate swaps are subject to certain customary provisions that could allow the counterparty to request immediate settlement of the fair value liability or asset upon violation of any or all of the provisions. The Company was in compliance with all provisions of the interest rate swap agreements at March 31, 2021. ​ Accounts Receivable Securitization Program The Company’s accounts receivable securitization program, which matures on October 1, 2021, allows for cash proceeds of $125.0 million to be provided under the program and has an accordion feature allowing the Company to request additional borrowings up to $25.0 million, subject to certain conditions. ​ Under this program, certain subsidiaries of the Company continuously sell a designated pool of trade accounts receivables to a wholly owned subsidiary which, in turn, may borrow funds on a revolving basis. This wholly owned consolidated subsidiary is a separate bankruptcy-remote entity, and its assets would be available only to satisfy the claims related to the lender’s interest in the trade accounts receivables. Borrowings under the accounts receivable securitization program bear interest based upon LIBOR, plus a margin, and an annual facility fee. The securitization agreement contains representations and warranties, affirmative and negative covenants, and events of default that are customary for financings of this type, including a maximum adjusted leverage ratio covenant. The Company was in compliance with the covenants under the accounts receivable securitization program at March 31, 2021. ​ The accounts receivable securitization program includes a provision under which the Company may request and the letter of credit issuer may issue standby letters of credit, primarily in support of workers’ compensation and third-party casualty claims liabilities in various states in which the Company is self-insured. The outstanding standby letters of credit reduce the availability of borrowings under the program. As of March 31, 2021, standby letters of credit of $11.7 million have been issued under the program, which reduced the available borrowing capacity to $113.3 million. ​ Letter of Credit Agreements and Surety Bond Programs As of March 31, 2021, the Company had letters of credit outstanding of $12.3 million (including $11.7 million issued under the accounts receivable securitization program). The Company has programs in place with multiple surety companies for the issuance of surety bonds in support of its self-insurance program. As of March 31, 2021, surety bonds outstanding related to the self-insurance program totaled $61.6 million.

POSTRETIREMENT BENEFIT PLANS

POSTRETIREMENT BENEFIT PLANS	3 Months Ended
	Mar. 31, 2021
POSTRETIREMENT BENEFIT PLANS
POSTRETIREMENT BENEFIT PLANS	NOTE G – POSTRETIREMENT BENEFIT PLANS ​ Supplemental Benefit and Postretirement Health Benefit Plans ​ The following is a summary of the components of net periodic benefit cost: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31 ​ ​ ​ Supplemental ​ Postretirement ​ ​ ​ Benefit Plan ​ Health Benefit Plan ​ ​ 2021 2020 2021 2020 ​ ​ (in thousands) ​ Service cost ​ $ — ​ $ — ​ $ 48 ​ $ 47 ​ Interest cost ​ 1 ​ 3 ​ 107 ​ 144 ​ Pension settlement expense (1) ​ — ​ 89 ​ — ​ — ​ Amortization of net actuarial (gain) loss (2) ​ 2 ​ 4 ​ (137) ​ (149) ​ Net periodic benefit cost (3) ​ $ 3 ​ $ 96 ​ $ 18 ​ $ 42 ​ ​ ​ (1) For the three months ended March 31, 2020, pension settlement expense for the supplemental benefit pension plan of $0.1 million (pre-tax), or $0.1 million (after-tax), was due to a $0.7 million benefit related to an officer retirement. (2) The Company amortizes actuarial gains and losses over the average remaining active service period of the plan participants and does not use a corridor approach. (3) Service cost is reported within operating expenses and the other components of net periodic benefit cost (including pension settlement expense) are reported within the other line item of other income (costs) in the consolidated statements of operations. ​ ​ Multiemployer Plans ​ ABF Freight System, Inc. and certain other subsidiaries reported in the Company’s Asset-Based operating segment (“ABF Freight”) contribute to multiemployer pension and health and welfare plans, which have been established pursuant to the Taft-Hartley Act, to provide benefits for its contractual employees. The 25 multiemployer pension plans to which ABF Freight contributes vary greatly in size and in funded status. Contributions to these plans are based generally on the time worked by ABF Freight’s contractual employees at rates specified in the 2018 ABF NMFA and other related supplemental agreements. ABF Freight recognizes as expense the contractually required contributions for each period and recognizes as a liability any contributions due and unpaid. The funding obligations to the multiemployer pension plans are intended to satisfy the requirements imposed by the Pension Protection Act of 2006, which was permanently extended by the Multiemployer Pension Reform Act (the “Reform Act”) included in the Consolidated and Further Continuing Appropriations Act of 2015. ​ Approximately one half of ABF Freight’s total contributions to multiemployer pension plans are made to the Central States, Southeast and Southwest Areas Pension Plan (the “Central States Pension Plan”). As set forth in the 2020 Annual Funding Notice for the Central States Pension Plan, the funded percentage of the plan was 19.5% as of January 1, 2020. In the Notice of Critical and Declining Status for the Central States Pension Plan dated March 31, 2021, the plan’s actuary certified that the plan is in critical and declining status, as defined by the Reform Act, for the plan year beginning January 1, 2021. Critical and declining status is applicable to critical status plans that are projected to become insolvent anytime within the next 14 plan years, or if the plan is projected to become insolvent within the next 19 plan years and either the plan’s ratio of inactive participants to active participants exceeds two to one or the plan’s funded percentage is less than 80% . ​ On March 11, 2021, H.R.1319, the American Rescue Plan Act of 2021 Butch Lewis Emergency Pension Plan Relief Act of 2021 ​ Through the term of the 2018 ABF NMFA, which extends through June 30, 2023, ABF Freight’s multiemployer pension contribution obligations generally will be satisfied by making the specified contributions when due. Future contribution rates will be determined through the negotiation process for contract periods following the term of the current collective bargaining agreement. While the Company cannot determine with any certainty the contributions that will be required under future collective bargaining agreements for ABF Freight’s contractual employees, management believes future contribution rates to multiemployer pension plans may be less likely to increase as a result of the provisions of the Pension Relief Act. If ABF Freight was to completely withdraw from certain multiemployer pension plans, under current law, ABF Freight would have material liabilities for its share of the unfunded vested liabilities of each such plan. More information will become available as the PBGC develops and issues regulations to implement the financial assistance program provided by the American Rescue Plan Act. ​ The multiemployer plan administrators have provided to the Company no other significant changes in information related to multiemployer plans from the information disclosed in the Company’s 2020 Annual Report on Form 10-K.

STOCKHOLDERS' EQUITY

STOCKHOLDERS' EQUITY	3 Months Ended
	Mar. 31, 2021
STOCKHOLDERS' EQUITY
STOCKHOLDERS' EQUITY	NOTE H – STOCKHOLDERS’ EQUITY ​ Accumulated Other Comprehensive Income ​ Components of accumulated other comprehensive income were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31 December 31 ​ ​ 2021 2020 ​ ​ (in thousands) ​ Pre-tax amounts: ​ ​ ​ ​ ​ ​ ​ Unrecognized net periodic benefit credit ​ $ 4,255 ​ $ 4,390 ​ Interest rate swap ​ ​ (843) ​ ​ (1,622) ​ Foreign currency translation ​ (735) ​ (1,182) ​ ​ ​ ​ ​ ​ ​ ​ ​ Total ​ $ 2,677 ​ $ 1,586 ​ ​ ​ ​ ​ ​ ​ ​ ​ After-tax amounts: ​ ​ ​ ​ ​ ​ ​ Unrecognized net periodic benefit credit ​ $ 3,160 ​ $ 3,260 ​ Interest rate swap ​ ​ (623) ​ ​ (1,198) ​ Foreign currency translation ​ (543) ​ (872) ​ ​ ​ ​ ​ ​ ​ ​ ​ Total ​ $ 1,994 ​ $ 1,190 ​ ​ ​ ​ The following is a summary of the changes in accumulated other comprehensive income (loss), net of tax, by component for the three months ended March 31, 2021 and 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unrecognized ​ ​ Interest Foreign ​ ​ ​ ​ ​ ​ Net Periodic ​ ​ Rate ​ Currency ​ ​ Total Benefit Costs ​ Swap Translation ​ ​ ​ (in thousands) ​ Balances at December 31, 2020 ​ $ 1,190 ​ $ 3,260 ​ $ (1,198) ​ $ (872) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other comprehensive income before reclassifications ​ 904 ​ — ​ ​ 575 ​ 329 ​ Amounts reclassified from accumulated other comprehensive loss ​ (100) ​ (100) ​ ​ — ​ — ​ Net current-period other comprehensive income (loss) ​ 804 ​ (100) ​ ​ 575 ​ 329 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balances at March 31, 2021 ​ $ 1,994 ​ $ 3,160 ​ $ (623) ​ $ (543) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balances at December 31, 2019 ​ ​ 203 ​ ​ 2,152 ​ ​ (416) ​ ​ (1,533) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other comprehensive loss before reclassifications ​ ​ (2,425) ​ ​ (8) ​ ​ (997) ​ ​ (1,420) ​ Amounts reclassified from accumulated other comprehensive income ​ ​ (42) ​ ​ (42) ​ ​ — ​ ​ — ​ Net current-period other comprehensive loss ​ ​ (2,467) ​ ​ (50) ​ ​ (997) ​ ​ (1,420) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balances at March 31, 2020 ​ $ (2,264) ​ $ 2,102 ​ $ (1,413) ​ $ (2,953) ​ ​ The following is a summary of the significant reclassifications out of accumulated other comprehensive income by component: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unrecognized Net Periodic ​ ​ ​ Benefit Credit (1)(2) ​ ​ Three Months Ended March 31 ​ ​ 2021 2020 ​ ​ (in thousands) Amortization of net actuarial gain ​ $ 135 ​ $ 145 ​ Pension settlement expense (3) ​ ​ — ​ (89) ​ Total, pre-tax ​ ​ 135 ​ 56 ​ Tax expense ​ ​ (35) ​ (14) ​ Total, net of tax ​ $ 100 ​ $ 42 ​ ​ (1) Amounts in parentheses indicate increases in expense or loss. (2) These components of accumulated other comprehensive income are included in the computation of net periodic benefit cost as disclosed in Note G. (3) For the three months ended March 31, 2020, pension settlement expense is related to the supplemental benefit plan (see Note G). ​ Dividends on Common Stock ​ The following table is a summary of dividends declared during the applicable quarter: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2021 ​ 2020 ​ ​ Per Share Amount Per Share Amount ​ ​ (in thousands, except per share data) First quarter ​ $ 0.08 ​ $ 2,037 ​ $ 0.08 ​ $ 2,033 ​ ​ On April 29, 2021, the Company’s Board of Directors declared a dividend of $0.08 per share to stockholders of record as of May 13, 2021. ​ Treasury Stock ​ The Company has a program to repurchase its common stock in the open market or in privately negotiated transactions. The program has no expiration date but may be terminated at any time at the Board of Directors’ discretion. Repurchases may be made using the Company’s cash reserves or other available sources. As of December 31, 2020, the Company had $6.6 million remaining under the program for repurchases of its common stock. On January 28, 2021 the Board of Directors extended the share repurchase program by authorizing a total of $50.0 million to be available for purchases of the Company’s common stock. During the three months ended March 31, 2021, the Company purchased 14,923 shares for an aggregate cost of $1.0 million, leaving $49.0 million available for repurchase of common stock under the program.

EARNINGS PER SHARE

EARNINGS PER SHARE	3 Months Ended
	Mar. 31, 2021
EARNINGS PER SHARE
EARNINGS PER SHARE	NOTE I – EARNINGS PER SHARE ​ The following table sets forth the computation of basic and diluted earnings per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31 ​ ​ 2021 2020 ​ ​ (in thousands, except share and per share data) Basic ​ ​ ​ ​ ​ ​ ​ Numerator: ​ ​ ​ ​ ​ ​ ​ Net income ​ $ 23,361 ​ $ 1,902 ​ Effect of unvested restricted stock awards ​ — ​ (1) ​ Adjusted net income ​ $ 23,361 ​ $ 1,901 ​ Denominator: ​ ​ ​ ​ ​ ​ ​ Weighted-average shares ​ 25,454,921 ​ 25,390,377 ​ Earnings per common share ​ $ 0.92 ​ $ 0.07 ​ ​ ​ ​ ​ ​ ​ ​ ​ Diluted ​ ​ ​ ​ ​ ​ ​ Numerator: ​ ​ ​ ​ ​ ​ ​ Net income ​ $ 23,361 ​ $ 1,902 ​ Effect of unvested restricted stock awards ​ — ​ (1) ​ Adjusted net income ​ $ 23,361 ​ $ 1,901 ​ Denominator: ​ ​ ​ ​ ​ ​ ​ Weighted-average shares ​ 25,454,921 ​ 25,390,377 ​ Effect of dilutive securities ​ 1,475,481 ​ 856,423 ​ Adjusted weighted-average shares and assumed conversions ​ 26,930,402 ​ 26,246,800 ​ Earnings per common share ​ $ 0.87 ​ $ 0.07 ​ ​

OPERATING SEGMENT DATA

OPERATING SEGMENT DATA	3 Months Ended
	Mar. 31, 2021
OPERATING SEGMENT DATA
OPERATING SEGMENT DATA	NOTE J – OPERATING SEGMENT DATA ​ The Company uses the “management approach” to determine its reportable operating segments, as well as to determine the basis of reporting the operating segment information. The management approach focuses on financial information that the Company’s management uses to make operating decisions. Management uses revenues, operating expense categories, operating ratios, operating income, and key operating statistics to evaluate performance and allocate resources to the Company’s operations. ​ Shared services represent costs incurred to support all segments, including sales, pricing, customer service, marketing, capacity sourcing functions, human resources, financial services, information technology, and other company-wide services. Certain overhead costs are not attributable to any segment and remain unallocated in “Other and eliminations.” Included in unallocated costs are expenses related to investor relations, legal, the ArcBest Board of Directors, and certain technology investments. Shared services costs attributable to the operating segments are predominantly allocated based upon estimated and planned resource utilization-related metrics such as estimated shipment levels, number of pricing proposals, or number of personnel supported. The bases for such charges are modified and adjusted by management when necessary or appropriate to reflect fairly and equitably the actual incidence of cost incurred by the operating segments. Management believes the methods used to allocate expenses are reasonable. ​ The Company’s reportable operating segments are impacted by seasonal fluctuations which affect tonnage, shipment or service event levels, and demand for services, as described below; therefore, operating results for the interim periods presented may not necessarily be indicative of the results for the fiscal year. ​ The Company’s reportable operating segments are as follows: ​ ● The Asset-Based segment includes the results of operations of ABF Freight System, Inc. and certain other subsidiaries. The segment operations include national, inter-regional, and regional transportation of general commodities through standard, expedited, and guaranteed LTL services. The Asset Based segment provides services to the ArcBest segment, including freight transportation related to certain consumer household goods self-move services. ​ Freight shipments and operating costs of the Asset-Based segment can be adversely affected by inclement weather conditions. The second and third calendar quarters of each year usually have the highest tonnage levels while the first quarter generally has the lowest, although other factors, including the state of the U.S. and global economies, available capacity in the market, and the impact of other adverse external events or conditions, including the COVID-19 pandemic, may influence quarterly freight tonnage levels. ​ ● The ArcBest segment includes the results of operations of the Company’s service offerings in ground expedite, truckload, dedicated, intermodal, household goods moving, managed transportation, warehousing and distribution, and international freight transportation for air, ocean, and ground. The ArcBest segment provides services to the Asset-Based segment. ​ ArcBest segment operations are influenced by seasonal fluctuations that impact customers’ supply chains. The second and third calendar quarters of each year usually have the highest shipment levels while the first quarter generally has the lowest, although other factors, including the state of the U.S. and global economies, available capacity in the market, and the impact of other adverse external events or conditions, including the COVID-19 pandemic, may impact quarterly business levels. Shipments of the ArcBest segment may decline during winter months because of post-holiday slowdowns, but expedite shipments can be subject to short-term increases depending on the impact of weather disruptions to customers’ supply chains. Plant shutdowns during summer months may affect shipments for automotive and manufacturing customers of the ArcBest segment, but severe weather events can result in higher demand for expedite services. Moving services of the ArcBest segment are impacted by seasonal fluctuations, generally resulting in higher business levels in the second and third quarters as the demand for moving services is typically stronger in the summer months. ​ ● FleetNet includes the results of operations of FleetNet America, Inc. and certain other subsidiaries that provide roadside assistance and maintenance management services for commercial vehicles through a network of third-party service providers. FleetNet provides services to the Asset-Based and ArcBest segments. ​ Emergency roadside service events of the FleetNet segment are favorably impacted by extreme weather conditions that affect commercial vehicle operations, and the segment’s results of operations will be influenced by seasonal variations in service event volume and the impact of other external events or conditions, including the COVID-19 pandemic. ​ The Company’s other business activities and operating segments that are not reportable include ArcBest Corporation and certain other subsidiaries. Certain costs incurred by the parent holding company and the Company’s shared services subsidiary are allocated to the reporting segments. The Company eliminates intercompany transactions in consolidation. However, the information used by the Company’s management with respect to its reportable segments is before intersegment eliminations of revenues and expenses. ​ Further classifications of operations or revenues by geographic location are impracticable and, therefore, are not provided. The Company’s foreign operations are not significant. ​ The following tables reflect reportable operating segment information: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31 ​ ​ 2021 2020 ​ ​ (in thousands) ​ REVENUES ​ ​ ​ ​ ​ ​ ​ Asset-Based ​ $ 556,292 ​ $ 515,713 ArcBest ​ 252,336 ​ 164,775 ​ FleetNet ​ 59,163 ​ 52,439 ​ Other and eliminations ​ (38,578) ​ (31,528) ​ Total consolidated revenues $ 829,213 $ 701,399 ​ ​ ​ ​ ​ ​ ​ ​ OPERATING EXPENSES ​ ​ ​ ​ ​ ​ ​ Asset-Based ​ ​ ​ ​ ​ ​ ​ Salaries, wages, and benefits ​ $ 285,694 ​ $ 283,838 Fuel, supplies, and expenses ​ 60,841 ​ 61,225 ​ Operating taxes and licenses ​ 12,248 ​ 12,794 ​ Insurance ​ 8,939 ​ 7,824 ​ Communications and utilities ​ 4,970 ​ 4,711 ​ Depreciation and amortization ​ 23,484 ​ 23,270 ​ Rents and purchased transportation ​ 75,588 ​ 55,770 ​ Shared services ​ ​ 55,866 ​ ​ 48,885 ​ Gain on sale of property and equipment (1) ​ (8,695) ​ (2,164) ​ Innovative technology costs (2) ​ 6,868 ​ 4,533 ​ Other ​ 434 ​ 1,787 ​ Total Asset-Based ​ 526,237 ​ 502,473 ​ ​ ​ ​ ​ ​ ​ ​ ​ ArcBest ​ ​ ​ ​ ​ ​ ​ Purchased transportation ​ 210,995 ​ 137,182 ​ Supplies and expenses ​ 2,568 ​ 2,280 ​ Depreciation and amortization ​ 2,386 ​ 2,470 ​ Shared services ​ ​ 26,072 ​ ​ 21,727 ​ Other ​ ​ 2,050 ​ 2,525 ​ Total ArcBest ​ 244,071 ​ 166,184 ​ ​ ​ ​ ​ ​ ​ ​ ​ FleetNet ​ 58,140 ​ 51,399 ​ Other and eliminations ​ (31,426) ​ (26,476) Total consolidated operating expenses ​ $ 797,022 ​ $ 693,580 ​ ​ ​ ​ ​ ​ ​ ​ ​ OPERATING INCOME ​ ​ ​ ​ ​ ​ ​ Asset-Based ​ $ 30,055 ​ $ 13,240 ​ ArcBest ​ 8,265 ​ (1,409) ​ FleetNet ​ 1,023 ​ 1,040 ​ Other and eliminations ​ (7,152) ​ (5,052) ​ Total consolidated operating income ​ $ 32,191 ​ $ 7,819 ​ OTHER INCOME (COSTS) ​ ​ ​ ​ ​ ​ ​ Interest and dividend income ​ $ 392 ​ $ 1,375 ​ Interest and other related financing costs ​ (2,428) ​ (2,947) ​ Other, net (3) ​ 1,192 ​ (3,862) ​ Total other income (costs) ​ (844) ​ (5,434) ​ INCOME BEFORE INCOME TAXES ​ $ 31,347 ​ $ 2,385 ​ ​ ​ (1) The three months ended March 31, 2021 includes an $8.6 million gain on the sale of an unutilized service center property. (2) Represents costs associated with the freight handling pilot test program at ABF Freight. (3) Includes the components of net periodic benefit cost other than service cost related to the Company’s SBP and postretirement plans (see Note G) and proceeds and changes in cash surrender value of life insurance policies. ​ ​ The following table reflects information about revenues from customers and intersegment revenues: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31 ​ ​ 2021 2020 ​ ​ (in thousands) ​ Revenues from customers ​ ​ ​ ​ ​ ​ ​ Asset-Based ​ $ 529,724 ​ $ 495,728 ArcBest ​ 250,241 ​ 162,948 ​ FleetNet ​ 48,434 ​ 41,744 ​ Other ​ 814 ​ 979 ​ Total consolidated revenues $ 829,213 $ 701,399 ​ ​ ​ ​ ​ ​ ​ ​ Intersegment revenues ​ ​ ​ ​ ​ ​ ​ Asset-Based ​ $ 26,568 ​ $ 19,985 ​ ArcBest ​ ​ 2,095 ​ ​ 1,827 ​ FleetNet ​ ​ 10,729 ​ ​ 10,695 ​ Other and eliminations ​ ​ (39,392) ​ ​ (32,507) ​ Total intersegment revenues ​ $ — $ — ​ ​ ​ ​ ​ ​ ​ ​ Total segment revenues ​ ​ ​ ​ ​ ​ ​ Asset-Based ​ $ 556,292 ​ $ 515,713 ​ ArcBest ​ ​ 252,336 ​ ​ 164,775 ​ FleetNet ​ ​ 59,163 ​ ​ 52,439 ​ Other and eliminations ​ ​ (38,578) ​ ​ (31,528) ​ Total consolidated revenues ​ $ 829,213 ​ $ 701,399 ​ ​ The following table presents operating expenses by category on a consolidated basis: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31 ​ ​ 2021 2020 ​ (in thousands) ​ OPERATING EXPENSES ​ ​ ​ ​ ​ ​ ​ Salaries, wages, and benefits ​ $ 359,395 ​ $ 344,946 ​ Rents, purchased transportation, and other costs of services ​ 309,338 ​ 217,028 ​ Fuel, supplies, and expenses ​ 73,149 ​ 71,773 ​ Depreciation and amortization (1) ​ 30,354 ​ 29,013 ​ Other ​ 24,786 ​ 30,820 ​ ​ ​ $ 797,022 ​ $ 693,580 ​ (1) Includes amortization of intangible assets.

LEGAL PROCEEDINGS, ENVIRONMENTA

LEGAL PROCEEDINGS, ENVIRONMENTAL MATTERS, AND OTHER EVENTS	3 Months Ended
	Mar. 31, 2021
LEGAL PROCEEDINGS, ENVIRONMENTAL MATTERS, AND OTHER EVENTS
LEGAL PROCEEDINGS, ENVIRONMENTAL MATTERS, AND OTHER EVENTS	NOTE K – LEGAL PROCEEDINGS, ENVIRONMENTAL MATTERS, AND OTHER EVENTS ​ The Company is involved in various legal actions arising in the ordinary course of business. The Company maintains liability insurance against certain risks arising out of the normal course of its business, subject to certain self-insured retention limits. The Company routinely establishes and reviews the adequacy of reserves for estimated legal, environmental, and self-insurance exposures. While management believes that amounts accrued in the consolidated financial statements are adequate, estimates of these liabilities may change as circumstances develop. Considering amounts recorded, routine legal matters are not expected to have a material adverse effect on the Company’s financial condition, results of operations, or cash flows. ​ Environmental Matters ​ The Company’s subsidiaries store fuel for use in tractors and trucks in underground tanks at certain facilities. Maintenance of such tanks is regulated at the federal and, in most cases, state levels. The Company believes it is in substantial compliance with all such regulations. The Company’s underground storage tanks are required to have leak detection systems. The Company is not aware of any leaks from such tanks that could reasonably be expected to have a material adverse effect on the Company. ​ The Company has received notices from the Environmental Protection Agency (the “EPA”) and others that it has been identified as a potentially responsible party under the Comprehensive Environmental Response Compensation and Liability Act, or other federal or state environmental statutes, at several hazardous waste sites. After investigating the Company’s involvement in waste disposal or waste generation at such sites, the Company has either agreed to de minimis settlements or determined that its obligations, other than those specifically accrued with respect to such sites, would involve immaterial monetary liability, although there can be no assurances in this regard. The Company maintains an accrual which is included in accrued expenses in the consolidated balance sheets, for estimated environmental cleanup costs of properties currently or previously operated by the Company. Amounts accrued reflect management’s best estimate of the future undiscounted exposure related to identified properties based on current environmental regulations, management’s experience with similar environmental matters, and testing performed at certain sites. ​ Certain Asset-Based service center facilities operate with no exposure certifications or stormwater permits under the federal Clean Water Act (“the CWA”). The no exposure certification and stormwater permits may require periodic facility inspections and monitoring and reporting of stormwater sampling results. The Company determined that certain procedures regarding sampling, documentation, and reporting were not appropriately being performed in accordance with the CWA. As such, the Company self-reported the matter to the EPA. An estimated settlement expense for this matter is accrued within accrued expenses in the consolidated balance sheet as of March 31, 2021. Resolution of this matter is not expected to have a material adverse effect on the Company’s financial condition, results of operations, or cash flows. ​ Other Events ​ In February 2021, the Company received a Notice of Assessment from a state pertaining to uncollected sales and use tax, including interest and penalties, for the period September 1, 2016 to November 30, 2018. The Company does not agree with the basis of the assessment and plans to appeal the assessment and defend its position. The Company has previously accrued an amount related to this assessment consistent with applicable accounting guidance, but if the state prevails in its position, the Company may owe additional tax. Management does not believe the amount involved will have a material adverse effect on the Company’s financial condition, results of operations, or cash flows. ​ ​

ORGANIZATION AND DESCRIPTION _2

ORGANIZATION AND DESCRIPTION OF THE BUSINESS AND FINANCIAL STATEMENT PRESENTATION (Policies)	3 Months Ended
	Mar. 31, 2021
ORGANIZATION AND DESCRIPTION OF THE BUSINESS AND FINANCIAL STATEMENT PRESENTATION
Financial Statement Presentation	Financial Statement Presentation ​ The accompanying unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States and applicable rules and regulations of the Securities and Exchange Commission (the “SEC”) pertaining to interim financial information. Accordingly, these interim financial statements do not include all information or footnote disclosures required by accounting principles generally accepted in the United States for complete financial statements and, therefore, should be read in conjunction with the audited financial statements and accompanying notes included in the Company’s 2020 Annual Report on Form 10-K and other current filings with the SEC. In the opinion of management, all adjustments (which are of a normal and recurring nature) considered necessary for a fair presentation have been included. ​ The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual amounts may differ from those estimates. The Company considered the impact of the novel coronavirus (“COVID-19”) pandemic on the estimates and assumptions used in preparation of the Company’s consolidated financial statements as of and for the three months ended March 31, 2021. Given the uncertainties regarding the economic environment and the impact of the COVID-19 pandemic on our business, it is possible that these estimates and assumptions may materially change in future periods.
Reclassifications	Reclassifications:
Adopted Accounting Pronouncements and Accounting Pronouncements Not Yet Adopted	Adopted Accounting Pronouncements ​ ASC Topic 740, Income Taxes ​ Accounting Pronouncements Not Yet Adopted ​ Management believes there is no other new accounting guidance issued but not yet effective that is relevant to the Company’s current financial statements.

FINANCIAL INSTRUMENTS AND FAI_2

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS (Tables)	3 Months Ended
	Mar. 31, 2021
FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS
Schedule components of cash and cash equivalents, short term investments, and restricted funds	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31 December 31 ​ ​ 2021 ​ 2020 ​ ​ ​ (in thousands) ​ Cash and cash equivalents ​ ​ ​ ​ ​ ​ ​ Cash deposits (1) ​ $ 236,380 ​ $ 240,687 ​ Variable rate demand notes (1)(2) ​ 29,161 ​ 29,066 ​ Money market funds (3) ​ 36,001 ​ 34,201 ​ Total cash and cash equivalents ​ $ 301,542 ​ $ 303,954 ​ ​ ​ ​ ​ ​ ​ ​ ​ Short-term investments ​ ​ ​ ​ ​ ​ ​ Certificates of deposit (1) ​ $ 59,316 ​ $ 53,297 ​ U.S. Treasury securities (4) ​ ​ — ​ ​ 12,111 ​ Total short-term investments ​ $ 59,316 ​ $ 65,408 ​ ​ (1) Recorded at cost plus accrued interest, which approximates fair value. (2) Amounts may be redeemed on a daily basis with the original issuer. (3) Recorded at fair value as determined by quoted market prices (see amounts presented in the table of financial assets and liabilities measured at fair value within this Note). (4) Recorded at amortized cost plus accrued interest, which approximates fair value. U.S. Treasury securities included in short-term investments are held-to-maturity investments with maturity dates of less than one year.
Schedule of fair value and carrying value disclosures of financial instruments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31 ​ December 31 ​ ​ 2021 2020 ​ ​ (in thousands) ​ ​ ​ ​ Carrying ​ Fair ​ Carrying ​ Fair ​ ​ ​ ​ Value ​ Value ​ Value ​ Value ​ Credit Facility (1) ​ $ 70,000 ​ $ 70,000 ​ $ 70,000 ​ $ 70,000 ​ Notes payable (2) ​ 196,830 ​ 201,282 ​ 214,216 ​ 217,226 ​ New England Pension Fund withdrawal liability (3) ​ ​ 21,250 ​ ​ 23,361 ​ ​ 21,407 ​ ​ 25,523 ​ ​ ​ $ 288,080 ​ $ 294,643 ​ $ 305,623 ​ $ 312,749 ​ ​ (1) The revolving credit facility (the “Credit Facility”) carries a variable interest rate based on LIBOR, plus a margin, that is considered to be priced at market for debt instruments having similar terms and collateral requirements (Level 2 of the fair value hierarchy). (2) Fair value of the notes payable was determined using a present value income approach based on quoted interest rates from lending institutions with which the Company would enter into similar transactions (Level 2 of the fair value hierarchy). (3) ABF Freight’s multiemployer pension plan obligation with the New England Teamsters and Trucking Industry Pension Fund (the “New England Pension Fund”) was restructured under a transition agreement effective on August 1, 2018, which resulted in a related withdrawal liability (see in Note I to the consolidated financial statements in Item 8 of the Company’s 2020 Annual Report on Form 10-K). The fair value of the outstanding withdrawal liability is equal to the present value of the future withdrawal liability payments, discounted at an interest rate of 3.4% and 2.6% at March 31, 2021 and December 31, 2020, respectively, determined using the 20-year U.S. Treasury rate plus a spread (Level 2 of the fair value hierarchy). Included in other long-term liabilities with the current portion included in accrued expenses.
Schedule of financial assets and liabilities measured at fair value on a recurring basis	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2021 ​ ​ ​ ​ ​ ​ Fair Value Measurements Using ​ ​ ​ ​ ​ ​ Quoted Prices Significant Significant ​ ​ ​ ​ ​ In Active ​ Observable ​ Unobservable ​ ​ ​ ​ ​ ​ Markets ​ Inputs ​ Inputs ​ ​ ​ Total (Level 1) (Level 2) (Level 3) ​ ​ (in thousands) ​ Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds (1) ​ $ 36,001 ​ $ 36,001 ​ $ — ​ $ — ​ Equity, bond, and money market mutual funds held in trust related to the Voluntary Savings Plan (2) ​ 3,017 ​ 3,017 ​ — ​ — ​ Interest rate swaps (3) ​ ​ 351 ​ ​ — ​ ​ 351 ​ ​ — ​ ​ ​ $ 39,369 ​ $ 39,018 ​ $ 351 ​ $ — ​ Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swaps (3) ​ $ 1,194 ​ $ — ​ $ 1,194 ​ $ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ ​ ​ ​ ​ ​ Fair Value Measurements Using ​ ​ ​ ​ ​ ​ Quoted Prices Significant Significant ​ ​ ​ ​ ​ In Active ​ Observable ​ Unobservable ​ ​ ​ ​ ​ ​ Markets ​ Inputs ​ Inputs ​ ​ ​ Total (Level 1) (Level 2) (Level 3) ​ ​ ​ (in thousands) ​ Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds (1) ​ $ 34,201 ​ $ 34,201 ​ $ — ​ $ — ​ Equity, bond, and money market mutual funds held in trust related to the Voluntary Savings Plan (2) ​ 2,955 ​ 2,955 ​ — ​ — ​ ​ ​ $ 37,156 ​ $ 37,156 ​ $ — ​ $ — ​ Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest rate swaps (3) ​ $ 1,622 ​ $ — ​ $ 1,622 ​ $ — ​ ​ (1) Included in cash and cash equivalents. (2) Nonqualified deferred compensation plan investments consist of U.S. and international equity mutual funds, government and corporate bond mutual funds, and money market funds which are held in a trust with a third-party brokerage firm. Included in other long-term assets, with a corresponding liability reported within other long-term liabilities. (3) Included in other long-term assets or other long-term liabilities. The fair values of the interest rate swaps were determined by discounting future cash flows and receipts based on expected interest rates observed in market interest rate curves adjusted for estimated credit valuation considerations reflecting nonperformance risk of the Company and the counterparty, which are considered to be in Level 3 of the fair value hierarchy. The Company assessed Level 3 inputs as insignificant to the valuation at March 31, 2021 and December 31, 2020 and considers the interest rate swap valuations in Level 2 of the fair value hierarchy.

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS (Tables)	3 Months Ended
	Mar. 31, 2021
GOODWILL AND INTANGIBLE ASSETS
Schedule of intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2021 ​ December 31, 2020 ​ ​ Weighted-Average ​ ​ ​ ​ Accumulated ​ Net ​ ​ ​ ​ Accumulated ​ Net ​ Amortization Period Cost Amortization Value ​ Cost Amortization Value ​ ​ (in years) ​ (in thousands) ​ (in thousands) Finite-lived intangible assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Customer relationships 14 ​ $ 52,721 ​ $ 31,429 ​ $ 21,292 ​ $ 52,721 ​ $ 30,477 ​ $ 22,244 ​ Other ​ 13 ​ ​ 994 ​ ​ 558 ​ ​ 436 ​ ​ 980 ​ ​ 543 ​ ​ 437 ​ ​ 14 ​ 53,715 ​ 31,987 ​ 21,728 ​ ​ 53,701 ​ 31,020 ​ 22,681 ​ Indefinite-lived intangible assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Trade name N/A ​ 32,300 ​ N/A ​ 32,300 ​ ​ 32,300 ​ N/A ​ 32,300 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total intangible assets N/A ​ $ 86,015 ​ $ 31,987 ​ $ 54,028 ​ $ 86,001 ​ $ 31,020 ​ $ 54,981 ​
Schedule of future amortization for intangible assets	​ ​ ​ ​ ​ ​ ​ Amortization of ​ ​ Intangible Assets ​ ​ ​ (in thousands) ​ Remainder of 2021 ​ $ 2,870 ​ 2022 ​ 3,815 ​ 2023 ​ 3,722 ​ 2024 ​ 3,689 ​ 2025 ​ ​ 3,674 ​ Thereafter ​ ​ 3,958 ​ Total amortization ​ $ 21,728 ​

LEASES (Tables)

LEASES (Tables)	3 Months Ended
	Mar. 31, 2021
LEASES
Schedule of components of lease expense	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, 2021 March 31, 2020 ​ ​ (in thousands) ​ Operating lease expense ​ $ 6,642 ​ $ 5,796 ​ Variable lease expense ​ ​ 1,332 ​ ​ 1,040 ​ Sublease income ​ ​ (155) ​ ​ (92) ​ ​ ​ ​ ​ ​ ​ ​ ​ Total operating lease expense (1) ​ $ 7,819 ​ $ 6,744 ​ (1) Operating lease expense excludes short-term leases with a term of 12 months or less.
Schedule of operating cash flows from operating lease activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31, 2021 ​ March 31, 2020 ​ ​ ​ (in thousands) ​ Noncash change in operating right-of-use assets ​ $ 5,741 ​ $ 5,815 ​ Change in operating lease liabilities ​ ​ (5,174) ​ ​ (5,953) ​ Operating right-of-use-assets and lease liabilities, net ​ $ 567 ​ $ (138) ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash paid for amounts included in the measurement of operating lease liabilities ​ $ (6,079) ​ $ (5,925) ​
Schedule of maturities of operating lease liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Equipment ​ ​ ​ ​ ​ ​ Land and ​ and ​ ​ Total Structures Other ​ (in thousands) ​ Remainder of 2021 ​ $ 18,816 ​ $ 18,748 ​ $ 68 ​ 2022 ​ 21,459 ​ 21,423 ​ 36 ​ 2023 ​ 17,248 ​ 17,223 ​ 25 ​ 2024 ​ 15,088 ​ 15,088 ​ — ​ 2025 ​ 12,561 ​ 12,561 ​ — ​ Thereafter ​ 43,109 ​ 43,109 ​ — ​ Total lease payments ​ ​ 128,281 ​ ​ 128,152 ​ ​ 129 ​ Less imputed interest ​ ​ (12,176) ​ ​ (12,174) ​ ​ (2) ​ Total ​ $ 116,105 ​ $ 115,978 ​ $ 127 ​

LONG-TERM DEBT AND FINANCING _2

LONG-TERM DEBT AND FINANCING ARRANGEMENTS (Tables)	3 Months Ended
	Mar. 31, 2021
LONG-TERM DEBT AND FINANCING ARRANGEMENTS
Schedule of long-term debt	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31 ​ December 31 ​ ​ 2021 2020 ​ ​ (in thousands) ​ Credit Facility (interest rate of 1.2% (1) ​ $ 70,000 ​ $ 70,000 ​ Notes payable (weighted-average interest rate of 3.0% at March 31, 2021) ​ 196,830 ​ 214,216 ​ Finance lease obligations (weighted-average interest rate of 3.3% at March 31, 2021) ​ 7 ​ 8 ​ ​ ​ 266,837 ​ 284,224 ​ Less current portion ​ 66,064 ​ 67,105 ​ Long-term debt, less current portion ​ $ 200,773 ​ $ 217,119 ​ ​ (1) The interest rate swap mitigates interest rate risk by effectively converting $50.0 million of borrowings under the Credit Facility from variable-rate interest to fixed-rate interest with a per annum rate of 3.12% based on the margin of the Credit Facility as of both March 31, 2021 and December 31, 2020. ​ ​
Scheduled maturities of long-term debt obligations	Scheduled maturities of long-term debt obligations as of March 31, 2021 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Credit ​ Notes ​ Finance Lease ​ ​ Total Facility (1) Payable Obligations ​ ​ (in thousands) ​ Due in one year or less $ 71,839 $ 899 $ 70,933 ​ $ 7 ​ Due after one year through two years ​ 60,650 ​ 1,005 ​ 59,645 ​ — ​ Due after two years through three years ​ 43,891 ​ 1,362 ​ 42,529 ​ — ​ Due after three years through four years ​ 98,088 ​ 70,854 ​ 27,234 ​ — ​ Due after four years through five years ​ 6,117 ​ — ​ 6,117 ​ — ​ Due after five years ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ Total payments ​ 280,585 ​ 74,120 ​ 206,458 ​ 7 ​ Less amounts representing interest ​ 13,748 ​ 4,120 ​ 9,628 ​ — ​ Long-term debt $ 266,837 $ 70,000 $ 196,830 ​ $ 7 ​ ​ (1) The future interest payments included in the scheduled maturities due are calculated using variable interest rates based on the LIBOR swap curve, plus the anticipated applicable margin.
Schedule of assets securing notes payable or held under capital leases	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31 ​ December 31 ​ ​ 2021 2020 ​ ​ (in thousands) Revenue equipment $ 325,562 $ 326,823 ​ Service, office, and other equipment ​ ​ 26,270 ​ ​ 26,270 ​ Total assets securing notes payable or held under finance leases ​ 351,832 ​ 353,093 ​ Less accumulated depreciation and amortization (1) ​ 126,398 ​ 115,424 ​ Net assets securing notes payable or held under finance leases ​ $ 225,434 ​ $ 237,669 ​ ​ ​ (1) Amortization of assets held under finance leases and depreciation of assets securing notes payable are included in depreciation expense. ​

PENSION AND OTHER POSTRETIREMEN

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Tables)	3 Months Ended
	Mar. 31, 2021
POSTRETIREMENT BENEFIT PLANS
Summary of the components of net periodic benefit cost	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31 ​ ​ ​ Supplemental ​ Postretirement ​ ​ ​ Benefit Plan ​ Health Benefit Plan ​ ​ 2021 2020 2021 2020 ​ ​ (in thousands) ​ Service cost ​ $ — ​ $ — ​ $ 48 ​ $ 47 ​ Interest cost ​ 1 ​ 3 ​ 107 ​ 144 ​ Pension settlement expense (1) ​ — ​ 89 ​ — ​ — ​ Amortization of net actuarial (gain) loss (2) ​ 2 ​ 4 ​ (137) ​ (149) ​ Net periodic benefit cost (3) ​ $ 3 ​ $ 96 ​ $ 18 ​ $ 42 ​ ​ ​ (1) For the three months ended March 31, 2020, pension settlement expense for the supplemental benefit pension plan of $0.1 million (pre-tax), or $0.1 million (after-tax), was due to a $0.7 million benefit related to an officer retirement. (2) The Company amortizes actuarial gains and losses over the average remaining active service period of the plan participants and does not use a corridor approach. (3) Service cost is reported within operating expenses and the other components of net periodic benefit cost (including pension settlement expense) are reported within the other line item of other income (costs) in the consolidated statements of operations.

STOCKHOLDERS' EQUITY (Tables)

STOCKHOLDERS' EQUITY (Tables)	3 Months Ended
	Mar. 31, 2021
STOCKHOLDERS' EQUITY
Components of accumulated other comprehensive income	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31 December 31 ​ ​ 2021 2020 ​ ​ (in thousands) ​ Pre-tax amounts: ​ ​ ​ ​ ​ ​ ​ Unrecognized net periodic benefit credit ​ $ 4,255 ​ $ 4,390 ​ Interest rate swap ​ ​ (843) ​ ​ (1,622) ​ Foreign currency translation ​ (735) ​ (1,182) ​ ​ ​ ​ ​ ​ ​ ​ ​ Total ​ $ 2,677 ​ $ 1,586 ​ ​ ​ ​ ​ ​ ​ ​ ​ After-tax amounts: ​ ​ ​ ​ ​ ​ ​ Unrecognized net periodic benefit credit ​ $ 3,160 ​ $ 3,260 ​ Interest rate swap ​ ​ (623) ​ ​ (1,198) ​ Foreign currency translation ​ (543) ​ (872) ​ ​ ​ ​ ​ ​ ​ ​ ​ Total ​ $ 1,994 ​ $ 1,190 ​
Summary of changes in accumulated other comprehensive income (loss), net of tax, by component	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unrecognized ​ ​ Interest Foreign ​ ​ ​ ​ ​ ​ Net Periodic ​ ​ Rate ​ Currency ​ ​ Total Benefit Costs ​ Swap Translation ​ ​ ​ (in thousands) ​ Balances at December 31, 2020 ​ $ 1,190 ​ $ 3,260 ​ $ (1,198) ​ $ (872) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other comprehensive income before reclassifications ​ 904 ​ — ​ ​ 575 ​ 329 ​ Amounts reclassified from accumulated other comprehensive loss ​ (100) ​ (100) ​ ​ — ​ — ​ Net current-period other comprehensive income (loss) ​ 804 ​ (100) ​ ​ 575 ​ 329 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balances at March 31, 2021 ​ $ 1,994 ​ $ 3,160 ​ $ (623) ​ $ (543) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balances at December 31, 2019 ​ ​ 203 ​ ​ 2,152 ​ ​ (416) ​ ​ (1,533) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other comprehensive loss before reclassifications ​ ​ (2,425) ​ ​ (8) ​ ​ (997) ​ ​ (1,420) ​ Amounts reclassified from accumulated other comprehensive income ​ ​ (42) ​ ​ (42) ​ ​ — ​ ​ — ​ Net current-period other comprehensive loss ​ ​ (2,467) ​ ​ (50) ​ ​ (997) ​ ​ (1,420) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balances at March 31, 2020 ​ $ (2,264) ​ $ 2,102 ​ $ (1,413) ​ $ (2,953) ​ ​
Summary of the significant reclassifications out of accumulated other comprehensive income (loss) by component	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unrecognized Net Periodic ​ ​ ​ Benefit Credit (1)(2) ​ ​ Three Months Ended March 31 ​ ​ 2021 2020 ​ ​ (in thousands) Amortization of net actuarial gain ​ $ 135 ​ $ 145 ​ Pension settlement expense (3) ​ ​ — ​ (89) ​ Total, pre-tax ​ ​ 135 ​ 56 ​ Tax expense ​ ​ (35) ​ (14) ​ Total, net of tax ​ $ 100 ​ $ 42 ​ ​ (1) Amounts in parentheses indicate increases in expense or loss. (2) These components of accumulated other comprehensive income are included in the computation of net periodic benefit cost as disclosed in Note G. (3) For the three months ended March 31, 2020, pension settlement expense is related to the supplemental benefit plan (see Note G).
Summary of dividends declared	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2021 ​ 2020 ​ ​ Per Share Amount Per Share Amount ​ ​ (in thousands, except per share data) First quarter ​ $ 0.08 ​ $ 2,037 ​ $ 0.08 ​ $ 2,033 ​

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	3 Months Ended
	Mar. 31, 2021
EARNINGS PER SHARE
Schedule of computation of basic and diluted earnings (loss) per share	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31 ​ ​ 2021 2020 ​ ​ (in thousands, except share and per share data) Basic ​ ​ ​ ​ ​ ​ ​ Numerator: ​ ​ ​ ​ ​ ​ ​ Net income ​ $ 23,361 ​ $ 1,902 ​ Effect of unvested restricted stock awards ​ — ​ (1) ​ Adjusted net income ​ $ 23,361 ​ $ 1,901 ​ Denominator: ​ ​ ​ ​ ​ ​ ​ Weighted-average shares ​ 25,454,921 ​ 25,390,377 ​ Earnings per common share ​ $ 0.92 ​ $ 0.07 ​ ​ ​ ​ ​ ​ ​ ​ ​ Diluted ​ ​ ​ ​ ​ ​ ​ Numerator: ​ ​ ​ ​ ​ ​ ​ Net income ​ $ 23,361 ​ $ 1,902 ​ Effect of unvested restricted stock awards ​ — ​ (1) ​ Adjusted net income ​ $ 23,361 ​ $ 1,901 ​ Denominator: ​ ​ ​ ​ ​ ​ ​ Weighted-average shares ​ 25,454,921 ​ 25,390,377 ​ Effect of dilutive securities ​ 1,475,481 ​ 856,423 ​ Adjusted weighted-average shares and assumed conversions ​ 26,930,402 ​ 26,246,800 ​ Earnings per common share ​ $ 0.87 ​ $ 0.07 ​

OPERATING SEGMENT DATA (Tables)

OPERATING SEGMENT DATA (Tables)	3 Months Ended
	Mar. 31, 2021
OPERATING SEGMENT DATA
Schedule of reportable operating segment information	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31 ​ ​ 2021 2020 ​ ​ (in thousands) ​ REVENUES ​ ​ ​ ​ ​ ​ ​ Asset-Based ​ $ 556,292 ​ $ 515,713 ArcBest ​ 252,336 ​ 164,775 ​ FleetNet ​ 59,163 ​ 52,439 ​ Other and eliminations ​ (38,578) ​ (31,528) ​ Total consolidated revenues $ 829,213 $ 701,399 ​ ​ ​ ​ ​ ​ ​ ​ OPERATING EXPENSES ​ ​ ​ ​ ​ ​ ​ Asset-Based ​ ​ ​ ​ ​ ​ ​ Salaries, wages, and benefits ​ $ 285,694 ​ $ 283,838 Fuel, supplies, and expenses ​ 60,841 ​ 61,225 ​ Operating taxes and licenses ​ 12,248 ​ 12,794 ​ Insurance ​ 8,939 ​ 7,824 ​ Communications and utilities ​ 4,970 ​ 4,711 ​ Depreciation and amortization ​ 23,484 ​ 23,270 ​ Rents and purchased transportation ​ 75,588 ​ 55,770 ​ Shared services ​ ​ 55,866 ​ ​ 48,885 ​ Gain on sale of property and equipment (1) ​ (8,695) ​ (2,164) ​ Innovative technology costs (2) ​ 6,868 ​ 4,533 ​ Other ​ 434 ​ 1,787 ​ Total Asset-Based ​ 526,237 ​ 502,473 ​ ​ ​ ​ ​ ​ ​ ​ ​ ArcBest ​ ​ ​ ​ ​ ​ ​ Purchased transportation ​ 210,995 ​ 137,182 ​ Supplies and expenses ​ 2,568 ​ 2,280 ​ Depreciation and amortization ​ 2,386 ​ 2,470 ​ Shared services ​ ​ 26,072 ​ ​ 21,727 ​ Other ​ ​ 2,050 ​ 2,525 ​ Total ArcBest ​ 244,071 ​ 166,184 ​ ​ ​ ​ ​ ​ ​ ​ ​ FleetNet ​ 58,140 ​ 51,399 ​ Other and eliminations ​ (31,426) ​ (26,476) Total consolidated operating expenses ​ $ 797,022 ​ $ 693,580 ​ ​ ​ ​ ​ ​ ​ ​ ​ OPERATING INCOME ​ ​ ​ ​ ​ ​ ​ Asset-Based ​ $ 30,055 ​ $ 13,240 ​ ArcBest ​ 8,265 ​ (1,409) ​ FleetNet ​ 1,023 ​ 1,040 ​ Other and eliminations ​ (7,152) ​ (5,052) ​ Total consolidated operating income ​ $ 32,191 ​ $ 7,819 ​ OTHER INCOME (COSTS) ​ ​ ​ ​ ​ ​ ​ Interest and dividend income ​ $ 392 ​ $ 1,375 ​ Interest and other related financing costs ​ (2,428) ​ (2,947) ​ Other, net (3) ​ 1,192 ​ (3,862) ​ Total other income (costs) ​ (844) ​ (5,434) ​ INCOME BEFORE INCOME TAXES ​ $ 31,347 ​ $ 2,385 ​ ​ ​ (1) The three months ended March 31, 2021 includes an $8.6 million gain on the sale of an unutilized service center property. (2) Represents costs associated with the freight handling pilot test program at ABF Freight. (3) Includes the components of net periodic benefit cost other than service cost related to the Company’s SBP and postretirement plans (see Note G) and proceeds and changes in cash surrender value of life insurance policies. ​
Schedule of revenues from customers and intersegment revenues	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31 ​ ​ 2021 2020 ​ ​ (in thousands) ​ Revenues from customers ​ ​ ​ ​ ​ ​ ​ Asset-Based ​ $ 529,724 ​ $ 495,728 ArcBest ​ 250,241 ​ 162,948 ​ FleetNet ​ 48,434 ​ 41,744 ​ Other ​ 814 ​ 979 ​ Total consolidated revenues $ 829,213 $ 701,399 ​ ​ ​ ​ ​ ​ ​ ​ Intersegment revenues ​ ​ ​ ​ ​ ​ ​ Asset-Based ​ $ 26,568 ​ $ 19,985 ​ ArcBest ​ ​ 2,095 ​ ​ 1,827 ​ FleetNet ​ ​ 10,729 ​ ​ 10,695 ​ Other and eliminations ​ ​ (39,392) ​ ​ (32,507) ​ Total intersegment revenues ​ $ — $ — ​ ​ ​ ​ ​ ​ ​ ​ Total segment revenues ​ ​ ​ ​ ​ ​ ​ Asset-Based ​ $ 556,292 ​ $ 515,713 ​ ArcBest ​ ​ 252,336 ​ ​ 164,775 ​ FleetNet ​ ​ 59,163 ​ ​ 52,439 ​ Other and eliminations ​ ​ (38,578) ​ ​ (31,528) ​ Total consolidated revenues ​ $ 829,213 ​ $ 701,399 ​
Schedule of consolidated operating expenses by component	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ March 31 ​ ​ 2021 2020 ​ (in thousands) ​ OPERATING EXPENSES ​ ​ ​ ​ ​ ​ ​ Salaries, wages, and benefits ​ $ 359,395 ​ $ 344,946 ​ Rents, purchased transportation, and other costs of services ​ 309,338 ​ 217,028 ​ Fuel, supplies, and expenses ​ 73,149 ​ 71,773 ​ Depreciation and amortization (1) ​ 30,354 ​ 29,013 ​ Other ​ 24,786 ​ 30,820 ​ ​ ​ $ 797,022 ​ $ 693,580 ​ (1) Includes amortization of intangible assets.

ORGANIZATION AND DESCRIPTION _3

ORGANIZATION AND DESCRIPTION OF THE BUSINESS AND FINANCIAL STATEMENT PRESENTATION - Organization (Details)	3 Months Ended
	Mar. 31, 2021segment
Organization and description of business
Number of reportable operating segments	3
Asset Based
Organization and description of business
Percentage of the Company's revenues, before other revenues and intercompany eliminations, represented by the Asset-Based segment	64.00%
Asset Based | Unionized employees concentration risk | Number of employees
Organization and description of business
Percentage of Asset-Based segment employees covered under collective bargaining agreement with the IBT	82.00%

FINANCIAL INSTRUMENTS AND FAI_3

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Cash and Cash Equivalents and Short-term Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Fair value disclosure
Cash and cash equivalents	$ 301,542	$ 303,954
Short-term investments	59,316	65,408
Concentrations of Credit Risk of Financial Instruments
Cash, cash equivalents and short-term investments not FDIC-insured	152,900	156,400
Cash deposits
Fair value disclosure
Cash and cash equivalents	236,380	240,687
Variable rate demand notes
Fair value disclosure
Cash and cash equivalents	29,161	29,066
Money market funds
Fair value disclosure
Cash and cash equivalents	36,001	34,201
Certificates of deposit
Fair value disclosure
Short-term investments	$ 59,316	53,297
U.S. Treasury securities
Fair value disclosure
Short-term investments		$ 12,111

FINANCIAL INSTRUMENTS AND FAI_4

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Debt (Details) $ in Thousands	Mar. 31, 2021USD ($)	Dec. 31, 2020USD ($)
Carrying Value
Fair value disclosure
Financial instruments	$ 288,080	$ 305,623
Fair Value
Fair value disclosure
Financial instruments	294,643	312,749
Credit Facility | Carrying Value | Level 2
Fair value disclosure
Financial instruments	70,000	70,000
Credit Facility | Fair Value | Level 2
Fair value disclosure
Financial instruments	70,000	70,000
Notes payable | Carrying Value | Level 2
Fair value disclosure
Financial instruments	196,830	214,216
Notes payable | Fair Value | Level 2
Fair value disclosure
Financial instruments	$ 201,282	$ 217,226
New England Pension Fund withdrawal liability | Discount Rate
Fair value disclosure
Measurement input	0.034	0.026
New England Pension Fund withdrawal liability | Carrying Value | Level 2
Fair value disclosure
Financial instruments	$ 21,250	$ 21,407
New England Pension Fund withdrawal liability | Fair Value | Level 2
Fair value disclosure
Financial instruments	$ 23,361	$ 25,523

FINANCIAL INSTRUMENTS AND FAI_5

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Assets and Liabilities (Details) - Recurring basis - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Assets:
Assets	$ 39,369	$ 37,156
Cash and cash equivalents
Assets:
Money market funds	36,001	34,201
Other long-term assets
Assets:
Equity, bond, and money market mutual funds held in trust related to the Voluntary Savings Plan	3,017	2,955
Interest rate swaps	351
Other long-term liabilities
Liabilities:
Interest rate swap	1,194	1,622
Level 1
Assets:
Assets	39,018	37,156
Level 1 | Cash and cash equivalents
Assets:
Money market funds	36,001	34,201
Level 1 | Other long-term assets
Assets:
Equity, bond, and money market mutual funds held in trust related to the Voluntary Savings Plan	3,017	2,955
Level 2
Assets:
Assets	351
Level 2 | Other long-term assets
Assets:
Interest rate swaps	351
Level 2 | Other long-term liabilities
Liabilities:
Interest rate swap	$ 1,194	$ 1,622

GOODWILL AND INTANGIBLE ASSET_2

GOODWILL AND INTANGIBLE ASSETS - Goodwill (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Goodwill by reportable operating segment
Goodwill	$ 88,320	$ 88,320
ArcBest
Goodwill by reportable operating segment
Goodwill	87,700	87,700
FleetNet
Goodwill by reportable operating segment
Goodwill	$ 600	$ 600

GOODWILL AND INTANGIBLE ASSET_3

GOODWILL AND INTANGIBLE ASSETS - Intangible (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Finite-lived intangible assets
Weighted Average Amortization Period	14 years
Cost	$ 53,715	$ 53,701
Accumulated Amortization	31,987	31,020
Net Value	21,728	22,681
Total intangible assets
Cost	86,015	86,001
Net Value	54,028	54,981
Trade name
Indefinite-lived intangible assets
Net Value	$ 32,300	32,300
Customer relationships
Finite-lived intangible assets
Weighted Average Amortization Period	14 years
Cost	$ 52,721	52,721
Accumulated Amortization	31,429	30,477
Net Value	$ 21,292	22,244
Other intangible assets
Finite-lived intangible assets
Weighted Average Amortization Period	13 years
Cost	$ 994	980
Accumulated Amortization	558	543
Net Value	$ 436	$ 437

GOODWILL AND INTANGIBLE ASSET_4

GOODWILL AND INTANGIBLE ASSETS - Amortization (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Future amortization for intangible assets
Remainder of 2021	$ 2,870
2022	3,815
2023	3,722
2024	3,689
2025	3,674
Thereafter	3,958
Net Value	$ 21,728	$ 22,681

INCOME TAXES - Tax Rate (Detail

INCOME TAXES - Tax Rate (Details)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
INCOME TAXES
Effective tax rate (as a percent)	25.50%	20.30%
State tax, low end of range of rate (as a percent)	6.00%
State tax, high end of range of rate (as a percent)	6.50%

INCOME TAXES - Allowance (Detai

INCOME TAXES - Allowance (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Valuation allowance	$ 1.4	$ 1.3

INCOME TAXES - Uncertain Tax Po

INCOME TAXES - Uncertain Tax Positions (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
INCOME TAXES
Reserve for uncertain tax positions	$ 0	$ 0.9

INCOME TAXES - Taxes Paid (Deta

INCOME TAXES - Taxes Paid (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Federal and state
Income taxes
Income taxes paid (in dollars)	$ 6.5
Federal and state | Maximum
Income taxes
Income tax refunds received (in dollars)	$ 0.1
State and foreign
Income taxes
Income taxes paid (in dollars)		$ 0.3
Federal
Income taxes
Income tax refunds received (in dollars)		$ 0.4

LEASES - Components of Lease Ex

LEASES - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
LEASES
Operating lease expense	$ 6,642	$ 5,796
Variable lease expense	1,332	1,040
Sublease income	(155)	(92)
Total operating lease expense	$ 7,819	$ 6,744

LEASES - Cash flows (Details)

LEASES - Cash flows (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating leases
Noncash change in operating right-of-use assets	$ 5,741	$ 5,815
Change in operating lease liabilities	(5,174)	(5,953)
Operating right-of-use assets and lease liabilities, net	567	(138)
Cash paid for amounts included in the measurement of operating lease liabilities	$ (6,079)	$ (5,925)

LEASES - Maturities of Operatin

LEASES - Maturities of Operating Lease Liabilities (Details) $ in Thousands	Mar. 31, 2021USD ($)
Maturities of operating lease liabilities
Remainder of 2021	$ 18,816
2022	21,459
2023	17,248
2024	15,088
2025	12,561
Thereafter	43,109
Total lease payments	128,281
Less imputed interest	(12,176)
Total operating lease liabilities	116,105
Land and Structures
Maturities of operating lease liabilities
Remainder of 2021	18,748
2022	21,423
2023	17,223
2024	15,088
2025	12,561
Thereafter	43,109
Total lease payments	128,152
Less imputed interest	(12,174)
Total operating lease liabilities	115,978
Equipment and Others
Maturities of operating lease liabilities
Remainder of 2021	68
2022	36
2023	25
Total lease payments	129
Less imputed interest	(2)
Total operating lease liabilities	$ 127

LONG-TERM DEBT AND FINANCING _3

LONG-TERM DEBT AND FINANCING ARRANGEMENTS - Summary (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Long-term debt obligations
Long-term debt	$ 266,837	$ 284,224
Less current portion	66,064	67,105
Long-term debt, less current portion	200,773	217,119
Payments under long-term debt obligations
2021	71,839
2022	60,650
2023	43,891
2024	98,088
2025	6,117
Total payments	280,585
Less amounts representing interest	13,748
Long-term debt	266,837	284,224
Credit Facility
Long-term debt obligations
Long-term debt	$ 70,000	70,000
Interest rate (as a percent)	1.20%
Payments under long-term debt obligations
2021	$ 899
2022	1,005
2023	1,362
2024	70,854
Total payments	74,120
Less amounts representing interest	4,120
Long-term debt	70,000	70,000
Credit Facility | Interest rate swap agreement, maturing on June 30, 2022
Long-term debt obligations
Amount of borrowings covered by the interest rate swap	$ 50,000	$ 50,000
Effective fixed interest rate on hedged borrowings (as a percent)	3.12%	3.12%
Notes payable
Long-term debt obligations
Long-term debt	$ 196,830	$ 214,216
Weighted-average interest rate (as a percent)	3.00%
Payments under long-term debt obligations
2021	$ 70,933
2022	59,645
2023	42,529
2024	27,234
2025	6,117
Total payments	206,458
Less amounts representing interest	9,628
Long-term debt	196,830	214,216
Finance lease obligations
Long-term debt obligations
Long-term debt	$ 7	8
Weighted-average interest rate (as a percent)	3.30%
Payments under long-term debt obligations
2021	$ 7
Total payments	7
Long-term debt	$ 7	$ 8

LONG-TERM DEBT AND FINANCING _4

LONG-TERM DEBT AND FINANCING ARRANGEMENTS - Assets securing notes (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Financing Arrangements
Total assets securing notes payable or held under finance leases	$ 351,832	$ 353,093
Less accumulated depreciation and amortization	126,398	115,424
Net assets securing notes payable or held under finance leases	225,434	237,669
Revenue equipment
Financing Arrangements
Total assets securing notes payable or held under finance leases	325,562	326,823
Service, office, and other equipment
Financing Arrangements
Total assets securing notes payable or held under finance leases	$ 26,270	$ 26,270

LONG-TERM DEBT AND FINANCING _5

LONG-TERM DEBT AND FINANCING ARRANGEMENTS - Credit Facility (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Financing Arrangements
Borrowings under credit facilities		$ 180,000
Repayment of debt	$ 17,387	$ 14,598
Credit Facility
Financing Arrangements
Maximum borrowing capacity	250,000
Additional borrowing capacity that may be requested	125,000
Remaining borrowing capacity	180,000
Swing Line Facility
Financing Arrangements
Maximum borrowing capacity	25,000
Letters of Credit, Sub-Facility
Financing Arrangements
Maximum borrowing capacity	$ 20,000

LONG-TERM DEBT AND FINANCING _6

LONG-TERM DEBT AND FINANCING ARRANGEMENTS - Interest rate swaps (Details) - USD ($) $ in Millions	Jun. 30, 2022	Mar. 31, 2021	Dec. 31, 2020	Jan. 02, 2020
Interest rate swap agreement, maturing on June 30, 2022
Financing Arrangements
Notional amount				$ 50
Fixed interest rate payments (as a percent)				1.99%
Interest rate swap agreement, maturing on June 30, 2022 | Other long-term liabilities
Financing Arrangements
Fair value of interest rate swap, liability		$ 1.2	$ 1.4
Interest rate swap agreement, maturing on June 30, 2022 | Credit Facility
Financing Arrangements
Amount of borrowings covered by the interest rate swap		$ 50	$ 50
Effective fixed interest rate on hedged borrowings (as a percent)		3.12%	3.12%
Amended interest rate swap agreement, maturing on October 1, 2024
Financing Arrangements
Notional amount		$ 50
Fixed interest rate payments (as a percent)		0.43%
Amended interest rate swap agreement, maturing on October 1, 2024 | Other long-term liabilities
Financing Arrangements
Fair value of interest rate swap, liability			$ 0.2
Amended interest rate swap agreement, maturing on October 1, 2024 | Other long-term assets
Financing Arrangements
Fair value of interest rate swap, asset		$ 0.4
Amended interest rate swap agreement, maturing on October 1, 2024 | Credit Facility | Forecast
Financing Arrangements
Amount of borrowings covered by the interest rate swap	$ 50
Effective fixed interest rate on hedged borrowings (as a percent)	1.56%

LONG-TERM DEBT AND FINANCING _7

LONG-TERM DEBT AND FINANCING ARRANGEMENTS - Securitization program (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Financing Arrangements
Long-term debt	$ 266,837	$ 284,224
Outstanding letters of credit	12,300
Accounts receivable securitization borrowings
Financing Arrangements
Maximum borrowing capacity	125,000
Additional borrowing capacity that may be requested	25,000
Outstanding letters of credit	11,700
Remaining borrowing capacity	$ 113,300

LONG-TERM DEBT AND FINANCING _8

LONG-TERM DEBT AND FINANCING ARRANGEMENTS - Letters of credit & Surety bonds (Details) $ in Millions	Mar. 31, 2021USD ($)
Financing Arrangements
Outstanding letters of credit	$ 12.3
Accounts receivable securitization borrowings
Financing Arrangements
Outstanding letters of credit	11.7
Surety bonds
Financing Arrangements
Outstanding surety bonds under uncollateralized bond programs	$ 61.6

POSTRETIREMENT BENEFIT PLANS -

POSTRETIREMENT BENEFIT PLANS - Components of cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Components of net periodic benefit cost
Pension settlement expense		$ 89
Supplemental Benefit Plan
Components of net periodic benefit cost
Interest cost	$ 1	3
Pension settlement expense		89
Amortization of net actuarial (gain) loss	2	4
Net periodic benefit cost	3	96
Postretirement Health Benefit Plan
Components of net periodic benefit cost
Service cost	48	47
Interest cost	107	144
Amortization of net actuarial (gain) loss	(137)	(149)
Net periodic benefit cost	$ 18	$ 42

POSTRETIREMENT BENEFIT PLANS _2

POSTRETIREMENT BENEFIT PLANS - Additional information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)
Postretirement benefit plans
Pension settlement expense	$ 89
Pension settlement expense, net of tax	66
Supplemental Benefit Plan
Postretirement benefit plans
Benefit	700
Pension settlement expense	89
Pension settlement expense, net of tax	$ 100

POSTRETIREMENT BENEFIT PLANS _3

POSTRETIREMENT BENEFIT PLANS - Multiemployer Plans (Details) - Nonunion Defined Benefit Pension Plan - Asset Based - plan	3 Months Ended
	Mar. 31, 2021	Jan. 01, 2020
Multiemployer Plans
Number of multiemployer plans to which ABF Freight currently contributes	25
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%
Central States Pension Plan
Multiemployer Plans
Approximate proportion of multiemployer pension plan contributions (as a percent)	50.00%
Actuarially certified projected funded percentage of multiemployer pension plan		19.50%

STOCKHOLDERS' EQUITY - AOCI (De

STOCKHOLDERS' EQUITY - AOCI (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Accumulated Other Comprehensive Income
Total after-tax amount	$ 851,909	$ 828,593	$ 759,206	$ 763,043
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income
Total pre-tax amount	2,677	1,586
Total after-tax amount	1,994	1,190	(2,264)	203
Unrecognized Net Periodic Benefit Credit
Accumulated Other Comprehensive Income
Total pre-tax amount	4,255	4,390
Total after-tax amount	3,160	3,260	2,102	2,152
Interest Rate Swap
Accumulated Other Comprehensive Income
Total pre-tax amount	(843)	(1,622)
Total after-tax amount	(623)	(1,198)	(1,413)	(416)
Foreign Currency Translation
Accumulated Other Comprehensive Income
Total pre-tax amount	(735)	(1,182)
Total after-tax amount	$ (543)	$ (872)	$ (2,953)	$ (1,533)

STOCKHOLDERS' EQUITY - AOCI com

STOCKHOLDERS' EQUITY - AOCI components (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Changes in accumulated other comprehensive income (loss), net of tax, by component
Balances	$ 828,593	$ 763,043
OTHER COMPREHENSIVE INCOME (LOSS), net of tax	804	(2,467)
Balances	851,909	759,206
Accumulated Other Comprehensive Income (Loss)
Changes in accumulated other comprehensive income (loss), net of tax, by component
Balances	1,190	203
Other comprehensive income (loss) before reclassifications	904	(2,425)
Amounts reclassified from accumulated other comprehensive income (loss)	(100)	(42)
OTHER COMPREHENSIVE INCOME (LOSS), net of tax	804	(2,467)
Balances	1,994	(2,264)
Unrecognized Net Periodic Benefit Credit
Changes in accumulated other comprehensive income (loss), net of tax, by component
Balances	3,260	2,152
Other comprehensive income (loss) before reclassifications		(8)
Amounts reclassified from accumulated other comprehensive income (loss)	(100)	(42)
OTHER COMPREHENSIVE INCOME (LOSS), net of tax	(100)	(50)
Balances	3,160	2,102
Interest Rate Swap
Changes in accumulated other comprehensive income (loss), net of tax, by component
Balances	(1,198)	(416)
Other comprehensive income (loss) before reclassifications	575	(997)
OTHER COMPREHENSIVE INCOME (LOSS), net of tax	575	(997)
Balances	(623)	(1,413)
Foreign Currency Translation
Changes in accumulated other comprehensive income (loss), net of tax, by component
Balances	(872)	(1,533)
Other comprehensive income (loss) before reclassifications	329	(1,420)
OTHER COMPREHENSIVE INCOME (LOSS), net of tax	329	(1,420)
Balances	$ (543)	$ (2,953)

STOCKHOLDERS' EQUITY - Reclass

STOCKHOLDERS' EQUITY - Reclass (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Unrecognized Net Periodic Benefit Credit
Significant reclassifications out of accumulated other comprehensive loss by component
Total, pre-tax	$ 135	$ 56
Tax benefit (expense)	(35)	(14)
Total, net of tax	100	42
Amortization of net actuarial gain
Significant reclassifications out of accumulated other comprehensive loss by component
Total, pre-tax	$ 135	145
Pension settlement expense, including termination expense
Significant reclassifications out of accumulated other comprehensive loss by component
Total, pre-tax		$ (89)

STOCKHOLDERS' EQUITY - Dividend

STOCKHOLDERS' EQUITY - Dividends (Details) - USD ($) $ / shares in Units, $ in Thousands	Apr. 29, 2021	Mar. 31, 2021	Mar. 31, 2020
Dividends on Common Stock
Dividends declared (in dollars per share)		$ 0.08	$ 0.08
Dividend Amount		$ 2,037	$ 2,033
Subsequent Event
Dividends on Common Stock
Dividends declared (in dollars per share)	$ 0.08

STOCKHOLDERS' EQUITY - Treasury

STOCKHOLDERS' EQUITY - Treasury Stock (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Jan. 28, 2021	Dec. 31, 2020
Treasury Stock
Aggregate cost of shares repurchased during the period	$ 1,001	$ 3,162
Stock Repurchase Program
Treasury Stock
Amount of stock repurchases authorized			$ 50,000
Number of shares repurchased during the period	14,923
Aggregate cost of shares repurchased during the period	$ 1,000
Amount available for repurchase	$ 49,000			$ 6,600

EARNINGS PER SHARE - Basic and

EARNINGS PER SHARE - Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Basic, numerator:
Net income	$ 23,361	$ 1,902
Effect of unvested restricted stock unit awards		(1)
Adjusted net income	$ 23,361	$ 1,901
Basic, denominator:
Weighted-average shares	25,454,921	25,390,377
Earnings per common share (in dollars per share)	$ 0.92	$ 0.07
Diluted, numerator:
Net income	$ 23,361	$ 1,902
Effect of unvested restricted stock unit awards		(1)
Adjusted net income	$ 23,361	$ 1,901
Diluted, denominator:
Weighted-average shares	25,454,921	25,390,377
Effect of dilutive securities	1,475,481	856,423
Adjusted weighted-average shares and assumed conversions	26,930,402	26,246,800
Earnings per common share (in dollars per share)	$ 0.87	$ 0.07

OPERATING SEGMENT DATA - Revenu

OPERATING SEGMENT DATA - Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenues
Revenues	$ 829,213	$ 701,399
Asset Based
Revenues
Revenues	529,724	495,728
ArcBest
Revenues
Revenues	250,241	162,948
FleetNet
Revenues
Revenues	48,434	41,744
Operating Segments | Asset Based
Revenues
Revenues	556,292	515,713
Operating Segments | ArcBest
Revenues
Revenues	252,336	164,775
Operating Segments | FleetNet
Revenues
Revenues	59,163	52,439
Other and eliminations
Revenues
Revenues	$ (38,578)	$ (31,528)

OPERATING SEGMENT DATA - Operat

OPERATING SEGMENT DATA - Operating expenses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
OPERATING EXPENSES
Salaries, wages, and benefits	$ 359,395	$ 344,946
Fuel, supplies, and expenses	73,149	71,773
Depreciation and amortization	30,354	29,013
Gain on sale of property and equipment	(8,635)	(2,130)
Other	24,786	30,820
Total consolidated operating expenses	797,022	693,580
Operating Segments | Asset Based
OPERATING EXPENSES
Salaries, wages, and benefits	285,694	283,838
Fuel, supplies, and expenses	60,841	61,225
Operating taxes and licenses	12,248	12,794
Insurance	8,939	7,824
Communications and utilities	4,970	4,711
Depreciation and amortization	23,484	23,270
Rents and purchased transportation	75,588	55,770
Shared services	55,866	48,885
Gain on sale of property and equipment	(8,695)	(2,164)
Innovative technology costs	6,868	4,533
Other	434	1,787
Total consolidated operating expenses	526,237	502,473
Operating Segments | Asset Based | Land and structures (service centers)
OPERATING EXPENSES
Gain on sale of property and equipment	(8,600)
Operating Segments | ArcBest
OPERATING EXPENSES
Purchased transportation	210,995	137,182
Supplies and expenses	2,568	2,280
Depreciation and amortization	2,386	2,470
Shared services	26,072	21,727
Other	2,050	2,525
Total consolidated operating expenses	244,071	166,184
Operating Segments | FleetNet
OPERATING EXPENSES
Total consolidated operating expenses	58,140	51,399
Other and eliminations
OPERATING EXPENSES
Total consolidated operating expenses	$ (31,426)	$ (26,476)

OPERATING SEGMENT DATA - Income

OPERATING SEGMENT DATA - Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
OPERATING INCOME
Operating income	$ 32,191	$ 7,819
OTHER INCOME (COSTS)
Interest and dividend income	392	1,375
Interest and other related financing costs	(2,428)	(2,947)
Other, net	1,192	(3,862)
TOTAL OTHER INCOME (COSTS)	(844)	(5,434)
INCOME BEFORE INCOME TAXES	31,347	2,385
Operating Segments | Asset Based
OPERATING INCOME
Operating income	30,055	13,240
Operating Segments | ArcBest
OPERATING INCOME
Operating income	8,265	(1,409)
Operating Segments | FleetNet
OPERATING INCOME
Operating income	1,023	1,040
Other and eliminations
OPERATING INCOME
Operating income	$ (7,152)	$ (5,052)

OPERATING SEGMENT DATA - Reve_2

OPERATING SEGMENT DATA - Revenue from customers (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenues
Revenues	$ 829,213	$ 701,399
Asset Based
Revenues
Revenues	529,724	495,728
ArcBest
Revenues
Revenues	250,241	162,948
FleetNet
Revenues
Revenues	48,434	41,744
Other
Revenues
Revenues	814	979
Operating Segments | Asset Based
Revenues
Revenues	556,292	515,713
Operating Segments | ArcBest
Revenues
Revenues	252,336	164,775
Operating Segments | FleetNet
Revenues
Revenues	59,163	52,439
Other and eliminations
Revenues
Revenues	(38,578)	(31,528)
Intersegment revenues
Revenues
Revenues	(39,392)	(32,507)
Intersegment revenues | Asset Based
Revenues
Revenues	(26,568)	(19,985)
Intersegment revenues | ArcBest
Revenues
Revenues	(2,095)	(1,827)
Intersegment revenues | FleetNet
Revenues
Revenues	$ (10,729)	$ (10,695)

OPERATING SEGMENT DATA - Oper_2

OPERATING SEGMENT DATA - Operating Expenses by Category (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
OPERATING EXPENSES
Salaries, wages, and benefits	$ 359,395	$ 344,946
Rents, purchased transportation, and other costs of services	309,338	217,028
Fuel, supplies, and expenses	73,149	71,773
Depreciation and amortization	30,354	29,013
Other	24,786	30,820
Total consolidated operating expenses	$ 797,022	$ 693,580