Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating revenues	$ 482,802	$ 495,654
Operating expenses:
Salaries, wages and benefits	156,737	151,465
Fuel	32,060	52,760
Supplies and maintenance	47,115	47,657
Taxes and licenses	20,987	21,080
Insurance and claims	18,347	22,047
Depreciation	50,164	45,720
Rent and purchased transportation	117,976	113,748
Communications and utilities	3,909	3,678
Other	3,020	(686)
Total operating expenses	450,315	457,469
Operating income	32,487	38,185
Other expense (income):
Interest expense	494	475
Interest income	(990)	(631)
Other	45	90
Total other income	(451)	(66)
Income before income taxes	32,938	38,251
Income taxes	12,846	15,109
Net income	$ 20,092	$ 23,142
Earnings per share:
Basic	$ 0.28	$ 0.32
Diluted	0.28	0.32
Dividends declared per share	$ 0.060	$ 0.050
Weighted-average common shares outstanding:
Basic	72,025	72,067
Diluted	72,353	72,542