Consolidated Statements of Income (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Revenues	$ 5,447	$ 5,284
Operating expenses:
Compensation and benefits	1,218	1,139
Fuel	1,159	1,122
Purchased services	653	617
Depreciation and amortization	515	483
Equipment rents	215	198
Materials and other	319	257
Total operating expenses	4,079	3,816
Operating income	1,368	1,468
Interest expense	196	178
Other expense, net	3	1
Income before income taxes	1,169	1,289
Income tax expense	445	491
Net income	$ 724	$ 798