CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Revenues:
Transportation	$ 2,803,704	$ 2,603,182
Sourcing	335,808	387,852
Payment Services	3,073	3,233
Total revenues	3,142,585	2,994,267
Costs and expenses:
Purchased transportation and related services	2,375,825	2,181,930
Purchased products sourced for resale	308,962	356,006
Purchased payment services	563	609
Personnel expenses	220,297	212,645
Other selling, general, and administrative expenses	79,967	74,371
Total costs and expenses	2,985,614	2,825,561
Income from operations	156,971	168,706
Investment and other (expense) income	(6,131)	(60)
Income before provision for income taxes	150,840	168,646
Provision for income taxes	57,653	65,303
Net income	93,187	103,343
Other comprehensive loss	(337)	(2,229)
Comprehensive income	$ 92,850	$ 101,114
Basic net income per share (in dollars per share)	$ 0.63	$ 0.64
Diluted net income per share (in dollars per share)	$ 0.63	$ 0.64
Basic weighted average shares outstanding (in shares)	148,517	160,637
Dilutive effect of outstanding stock awards (in shares)	491	53
Diluted weighted average shares outstanding (in shares)	149,008	160,690