Goodwill and other intangible assets - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	$ 24,664		$ 26,639
Amortization charges associated with finite-lived intangible assets	1,200	$ 1,200
Total estimated amortization of finite-lived intangible assets for the remainder of the year	3,100
Total estimated amortization of finite-lived intangible assets for 2026	3,700
Total estimated amortization of finite-lived intangible assets for 2027	3,700
Total estimated amortization of finite-lived intangible assets for 2028	2,800
Total estimated amortization of finite-lived intangible assets for 2029	2,200
Total estimated amortization of finite-lived intangible assets for 2030	2,100
Developed-product-technology rights
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, net	24,081		$ 26,017
Developed-product-technology rights | Otezla
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, fair value disclosure	4,000
Finite-lived intangible assets, net	4,800
Impairment charge	$ 800