Income taxes - Narrative (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Income Tax Examination, Year under Examination	2014 2015 2016 2017 2018 2019
Income tax liabilities with federal taxing authority settled through year	2013
Income tax liabilities with state and foreign jurisdictions estimated settlement year	2025
Unrecognized tax benefits	$ 501	$ 480
Unrecognized tax benefits that would impact effective tax rate	$ 448