CONSOLIDATED INCOME STATEMENTS - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 30, 2016
Income Statement [Abstract]
Revenue	$ 12,250	$ 11,408	$ 11,069
Expense
Labor and Fringe	2,738	2,946	3,135
Materials, Supplies and Other	1,967	2,113	2,092
Depreciation	1,331	1,315	1,301
Fuel	1,046	864	713
Equipment and Other Rents	395	429	465
Restructuring Charge (Note 1)	0	240	0
Equity Earnings of Affiliates	(96)	(219)	(50)
Total Expense	7,381	7,688	7,656
Operating Income	4,869	3,720	3,413
Interest Expense	(639)	(546)	(579)
Debt Repurchase Expense	0	0	(115)
Restructuring Charge - Non-Operating (Note 1)	0	(85)	0
Other Income - Net (Note 10)	74	53	22
Earnings Before Income Taxes	4,304	3,142	2,741
Income Tax (Expense) Benefit (Note 11)	(995)	2,329	(1,027)
Net Earnings	$ 3,309	$ 5,471	$ 1,714
Net Earnings Per Share
Basic (in dollars per share)	$ 3.86	$ 6.01	$ 1.81
Assuming Dilution (in dollars per share)	$ 3.84	$ 5.99	$ 1.81
Average Common Shares Outstanding (Millions)
Basic (shares)	857	911	947
Assuming Dilution (shares)	861	914	948
Cash Dividends Paid Per Common Share (in dollars per share)	$ 0.88	$ 0.78	$ 0.72