Consolidated Statements of Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues	$ 19,829	$ 21,967	$ 23,239
Operating expenses:
Compensation and benefits	4,769	5,043	5,023
Purchased services	2,418	2,546	2,592
Depreciation and amortization	2,128	2,001	2,123
Fuel	1,934	2,656	4,478
Equipment rents	766	801	867
Materials and other	1,129	1,196	1,143
Total operating expenses	13,144	14,243	16,226
Operating income	6,685	7,724	7,013
Interest expense	992	928	833
Other expense, net	0	21	11
Income before income taxes	5,693	6,775	6,169
Income tax expense	2,124	2,527	2,300
Net income	$ 3,569	$ 4,248	$ 3,869