Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues	$ 5,893	$ 5,878	$ 11,655	$ 11,502
Operating expenses:
Compensation and benefits	1,334	1,328	2,734	2,643
Purchased services	687	714	1,400	1,406
Fuel	775	830	1,486	1,597
Depreciation and amortization	595	575	1,186	1,146
Equipment rents	187	167	378	359
Materials and other	308	381	685	721
Total operating expenses	3,886	3,995	7,869	7,872
Operating income	2,007	1,883	3,786	3,630
Interest expense	267	256	535	512
Other (income) expense, net	(33)	(28)	(187)	(50)
Income before income taxes	1,773	1,655	3,438	3,168
Income tax expense	435	346	847	714
Net income	$ 1,338	$ 1,309	$ 2,591	$ 2,454