Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues	$ 5,624	$ 5,185
Operating expenses:
Compensation and benefits	1,315	1,297
Purchased services	692	626
Fuel	767	605
Depreciation and amortization	571	573
Equipment rents	192	196
Materials and other	340	308
Total operating expenses	3,877	3,605
Operating income	1,747	1,580
Interest expense	256	252
Other (income) expense, net	(22)	(17)
Income before income taxes	1,513	1,345
Income tax expense	368	507
Net income	$ 1,145	$ 838