Condensed Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenues:
Total revenues	$ 4,803,869	$ 3,805,008
Costs and expenses:
Personnel expenses	360,835	330,220
Other selling, general, and administrative expenses	118,216	128,293
Total costs and expenses	4,580,540	3,695,568
Income from operations	223,329	109,440
Interest and other expense	(11,260)	(15,228)
Income before provision for income taxes	212,069	94,212
Provision for income taxes	38,764	16,066
Net income	173,305	78,146
Other comprehensive loss, net of tax	(7,286)	(32,195)
Comprehensive income	$ 166,019	$ 45,951
Basic net income per share (in dollars per share)	$ 1.29	$ 0.58
Diluted net income per share (in dollars per share)	$ 1.28	$ 0.57
Basic weighted average shares outstanding (shares)	134,508	135,474
Dilutive effect of outstanding stock awards (shares)	1,237	495
Diluted weighted average shares outstanding (shares)	135,745	135,969
Transportation
Revenues:
Total revenues	$ 4,560,227	$ 3,542,118
Costs and expenses:
Purchased products and services	3,881,285	3,000,113
Sourcing
Revenues:
Total revenues	243,642	262,890
Costs and expenses:
Purchased products and services	$ 220,204	$ 236,942