Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
CURRENT ASSETS
Cash and cash equivalents	$ 167,241	$ 113,852
Trade receivables, net of $1.1 million allowance in 2021 and 2020, respectively	59,290	55,577
Prepaid tires	8,768	8,241
Other current assets	12,212	15,342
Total current assets	247,511	193,012
PROPERTY AND EQUIPMENT
Land and land improvements	83,123	77,525
Buildings	87,730	86,712
Furniture and fixtures	5,142	4,807
Shop and service equipment	14,766	14,380
Revenue equipment	542,533	590,153
Construction in progress	11,597	5,783
Property, Plant and Equipment, Gross	744,891	779,360
Less accumulated depreciation	244,510	240,080
Property and equipment, net	500,381	539,280
GOODWILL	168,295	168,295
OTHER INTANGIBLES, NET	23,550	24,746
OTHER ASSETS	17,248	17,679
Deferred Income Taxes, Net	0	8,164
Assets	956,985	951,176
CURRENT LIABILITIES
Accounts payable and accrued liabilities	18,952	12,751
Compensation and benefits	24,002	22,422
Insurance accruals	14,521	15,837
Other Accrued Liabilities	18,654	18,557
Accrued Income Taxes, Current	1,090	1,475
Total current liabilities	77,219	71,042
LONG-TERM LIABILITIES
Income taxes payable	5,306	5,801
Deferred Tax and Other Liabilities, Noncurrent	90,471	104,004
Insurance accruals less current portion	42,223	45,995
Total long-term liabilities	138,000	155,800
COMMITMENTS AND CONTINGENCIES (Note 13)
STOCKHOLDERS' EQUITY
Preferred Stock, Value, Issued	0	0
Capital stock, common, $.01 par value; authorized 395,000 shares; issued 90,689 in 2021 and 2020; outstanding 79,913 and 80,653 in 2021 and 2020, respectively	907	907
Additional paid-in capital	4,531	4,330
Retained earnings	922,249	890,970
Treasury stock, at cost; 10,776 and 10,036 shares in 2021 and 2020, respectively	(185,921)	(171,873)
Stockholders' Equity Attributable to Parent	741,766	724,334
Liabilities and Stockholders' Equity	$ 956,985	$ 951,176