Restructuring Costs - Restructuring and Related Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 780	$ 299	$ 90
Gain (loss) on divestiture	586
(Gains) losses reclassified to earnings	494
Rail
Restructuring Cost and Reserve [Line Items]
Restructuring costs		193
Other restructuring costs
Restructuring Cost and Reserve [Line Items]
Restructuring costs	110	215	59
Other operating income (expense) | Employee separation
Restructuring Cost and Reserve [Line Items]
Restructuring costs	74	77	92
Other operating income (expense) | Longwall divestiture
Restructuring Cost and Reserve [Line Items]
Restructuring costs	586	0	0
Other operating income (expense) | Contract termination
Restructuring Cost and Reserve [Line Items]
Restructuring costs	7	1	2
Other operating income (expense) | Long-lived asset impairments
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 3	$ 6	$ (63)