Consolidated Condensed Statements of Earnings (Unaudited) (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Consolidated Condensed Statements of Earnings [Abstract]
Revenue	$ 1,513,344	$ 1,286,123	$ 2,938,720	$ 2,506,061
Operating expense (exclusive of items shown separately)	738,466	611,495	1,432,889	1,189,109
Salaries and employee-related costs	370,367	310,241	735,762	614,953
Subcontracted transportation	83,193	64,585	166,275	124,922
Depreciation expense	214,858	206,761	420,795	417,766
Gains on vehicle sales, net	(15,658)	(6,587)	(28,007)	(11,105)
Equipment rental	14,729	16,614	28,962	33,069
Interest expense	32,974	31,152	67,393	64,488
Miscellaneous income, net	(595)	(345)	(4,737)	(1,840)
Restructuring and other charges, net			768
Total expenses	1,438,334	1,233,916	2,820,100	2,431,362
Earnings from continuing operations before income taxes	75,010	52,207	118,620	74,699
Provision for income taxes	34,096	21,607	51,849	31,227
Earnings from continuing operations	40,914	30,600	66,771	43,472
Loss from discontinued operations, net of tax	(881)	(759)	(1,613)	(1,258)
Net earnings	$ 40,033	$ 29,841	$ 65,158	$ 42,214
Earnings (loss) per common share - Basic
Continuing operations	$ 0.80	$ 0.58	$ 1.30	$ 0.82
Discontinued operations	$ (0.02)	$ (0.01)	$ (0.03)	$ (0.02)
Net earnings	$ 0.78	$ 0.57	$ 1.27	$ 0.80
Earnings (loss) per common share - Diluted
Continuing operations	$ 0.79	$ 0.58	$ 1.29	$ 0.82
Discontinued operations	$ (0.02)	$ (0.02)	$ (0.03)	$ (0.03)
Net earnings	$ 0.77	$ 0.56	$ 1.26	$ 0.79
Cash dividends declared and paid per common share	$ 0.27	$ 0.25	$ 0.54	$ 0.50