Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenues	$ 5,600	$ 5,881	$ 16,571	$ 17,063
Operating expenses:
Compensation and benefits	1,220	1,243	3,826	3,695
Fuel	670	1,123	2,080	3,438
Purchased services	633	637	1,909	1,924
Depreciation and amortization	503	531	1,488	1,569
Equipment rents	205	216	603	656
Materials and other	280	263	913	865
Total operating expenses	3,511	4,013	10,819	12,147
Operating income	2,089	1,868	5,752	4,916
Interest expense	238	211	683	613
Other expense, net	12	3	22	8
Income before income taxes	1,839	1,654	5,047	4,295
Income tax expense	683	619	1,883	1,620
Net income	$ 1,156	$ 1,035	$ 3,164	$ 2,675