Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Operating revenues:
Operating revenues	$ 6,269	$ 5,504	$ 12,129	$ 10,505
Operating expenses:
Compensation and benefits	1,092	1,022	2,193	2,048
Fuel	940	497	1,654	908
Purchased services and materials	622	478	1,183	968
Depreciation	559	550	1,114	1,099
Equipment and other rents	230	200	445	412
Other	331	284	668	604
Total operating expenses	3,774	3,031	7,257	6,039
Operating income	2,495	2,473	4,872	4,466
Other income, net (Note 6)	163	125	210	176
Interest expense	(316)	(282)	(623)	(572)
Income before income taxes	2,342	2,316	4,459	4,070
Income taxes (Note 7)	(507)	(518)	(994)	(931)
Net income	$ 1,835	$ 1,798	$ 3,465	$ 3,139
Share and Per Share (Note 8):
Earnings per share - basic (in dollars per share)	$ 2.93	$ 2.73	$ 5.51	$ 4.73
Earnings per share - diluted (in dollars per share)	$ 2.93	$ 2.72	$ 5.50	$ 4.72
Weighted average number of shares - basic (in shares)	625.6	658.5	628.9	663.1
Weighted average number of shares - diluted (in shares)	626.8	660.1	630.2	664.7
Cargo and Freight [Member]
Operating revenues:
Operating revenues	$ 5,842	$ 5,132	$ 11,282	$ 9,781
Product and Service, Other [Member]
Operating revenues:
Operating revenues	$ 427	$ 372	$ 847	$ 724