Share-based compensation (Pre-tax and After-tax Share-based Compensation Expense) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based Payment Arrangement, Expense, Tax Benefit		$ 42	$ 19	$ 29
Restricted stock
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense, pre-tax		274	253	230
Share-based compensation expense, after-tax		210	202	179
Stock options
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense, pre-tax		83	71	60
Share-based compensation expense, after-tax	[1]	$ 49	$ 56	$ 38

[1] The windfall tax benefit recorded to Income tax expense in the Consolidated statement of operations was $42 million, $19 million, and $29 million for the years ended December 31, 2024, 2023, and 2022, respectively.