CONSOLIDATED INCOME STATEMENTS - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Revenue	$ 14,657	$ 14,853	$ 12,522
Expense
Labor and Fringe	3,024	2,861	2,550
Purchased Services and Other	2,764	2,685	2,135
Depreciation and Amortization	1,611	1,500	1,420
Fuel	1,377	1,626	913
Equipment and Other Rents	354	396	364
Gains on Property Dispositions	(34)	(238)	(454)
Total Expense	9,096	8,830	6,928
Operating Income	5,561	6,023	5,594
Interest Expense	(809)	(742)	(722)
Other Income - Net (Note 14)	139	133	79
Earnings Before Income Taxes	4,891	5,414	4,951
Income Tax Expense (Note 12)	(1,176)	(1,248)	(1,170)
Net Earnings	$ 3,715	$ 4,166	$ 3,781
Net Earnings Per Share
Basic (in dollars per share)	$ 1.85	$ 1.95	$ 1.68
Assuming Dilution (in dollars per share)	$ 1.85	$ 1.95	$ 1.68
Average Common Shares Outstanding (Millions)
Basic (shares)	2,008	2,136	2,250
Assuming Dilution (shares)	2,013	2,141	2,255