Stock-based compensation - Schedule of Components of Stock-based Compensation Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Components of stock-based compensation expense [Abstract]
Total stock-based compensation expense, pretax	$ 530	$ 473	$ 401
Tax benefit from stock-based compensation expense	(114)	(102)	(86)
Total stock-based compensation expense, net of tax	416	371	315
RSUs
Components of stock-based compensation expense [Abstract]
Total stock-based compensation expense, pretax	351	309	227
Performance units
Components of stock-based compensation expense [Abstract]
Total stock-based compensation expense, pretax	133	121	132
Stock options
Components of stock-based compensation expense [Abstract]
Total stock-based compensation expense, pretax	$ 46	$ 43	$ 42