CONSOLIDATED INCOME STATEMENTS - USD ($) shares in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020		Dec. 31, 2019
Income Statement [Abstract]
Revenue		$ 12,522	$ 10,583		$ 11,937
Expense
Labor and Fringe		2,550	2,275		2,616
Purchased Services and Other	[1]	2,135	1,719		1,900
Depreciation		1,420	1,383		1,349
Fuel		913	541		906
Equipment and Other Rents		364	338		352
Gains on Property Dispositions		(454)	(35)		(151)
Total Expense		6,928	6,221		6,972
Operating Income		5,594	4,362		4,965
Interest Expense		(722)	(754)		(737)
Other Income - Net (Note 14)		79	19		88
Earnings Before Income Taxes		4,951	3,627		4,316
Income Tax Expense (Note 12)		(1,170)	(862)		(985)
Net Earnings		$ 3,781	$ 2,765		$ 3,331
Net Earnings Per Share
Basic (in dollars per share)		$ 1.68	$ 1.20	[2]	$ 1.39	[2]
Assuming Dilution (in dollars per share)		$ 1.68	$ 1.20	[2]	$ 1.39	[2]
Average Common Shares Outstanding (Millions)
Basic (shares)		2,250	2,300	[2]	2,389	[2]
Assuming Dilution (shares)		2,255	2,305	[2]	2,395	[2]

[1] Beginning third quarter 2021, the Company changed the name of Materials, Supplies and Other expense to Purchased Services and Other, which better describes the composition of this expense amount. This change in naming convention does not impact previously reported results.

[2] All prior period share and per share data has been retroactively adjusted to reflect the stock split effective June 28, 2021. Certain prior year data has been reclassified to conform to the current presentation.