Condensed Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 33,833	$ 10,171
Customer receivables, less allowances of $8,443 and $8,346, respectively	363,807	320,087
Other receivables	6,393	14,402
Prepaid expenses and other current assets	40,579	37,962
Total current assets	444,612	382,622
Property and equipment:
Revenue equipment	1,573,352	1,496,697
Land and structures	1,445,188	1,377,106
Other fixed assets	419,188	402,482
Leasehold improvements	8,617	8,699
Total property and equipment	3,446,345	3,284,984
Accumulated depreciation	(1,125,102)	(1,043,582)
Net property and equipment	2,321,243	2,241,402
Goodwill	19,463	19,463
Other assets	54,880	52,760
Total assets	2,840,198	2,696,247
Current liabilities:
Accounts payable	54,234	89,216
Compensation and benefits	145,760	129,170
Claims and insurance accruals	47,897	47,417
Other accrued liabilities	25,841	22,833
Income taxes payable	20,678	0
Current maturities of long-term debt	50,000	0
Total current liabilities	344,410	288,636
Long-term liabilities:
Long-term debt	45,000	104,975
Other non-current liabilities	185,198	178,879
Deferred income taxes	272,599	272,599
Total long-term liabilities	502,797	556,453
Total liabilities	847,207	845,089
Commitments and Contingencies
Shareholders' equity:
Common stock - $0.10 par value, 140,000,000 shares authorized, 82,387,823 and 82,416,657 shares outstanding at June 30, 2017 and December 31, 2016, respectively	8,239	8,242
Capital in excess of par value	136,707	135,466
Retained earnings	1,848,045	1,707,450
Total shareholders' equity	1,992,991	1,851,158
Total liabilities and shareholders' equity	$ 2,840,198	$ 2,696,247