Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenues	$ 5,167	$ 5,600	$ 14,519	$ 16,571
Operating expenses:
Compensation and benefits	1,193	1,220	3,535	3,826
Purchased services	562	633	1,789	1,909
Depreciation and amortization	534	503	1,584	1,488
Fuel	533	670	1,359	2,080
Equipment rents	198	205	570	603
Materials and other	267	280	810	913
Total operating expenses	3,287	3,511	9,647	10,819
Operating income	1,880	2,089	4,872	5,752
Interest expense	250	238	744	683
Other (income) expense, net	(3)	12	(1)	22
Income before income taxes	1,633	1,839	4,129	5,047
Income tax expense	613	683	1,553	1,883
Net income	$ 1,020	$ 1,156	$ 2,576	$ 3,164