Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Goodwill and Intangible Assets
Gross amount of amortizable intangible assets	$ 27,800	$ 27,600
Accumulated amortization of intangible assets	14,200	11,900
Increase (Decrease) in intangible assets due to foreign currency translation adjustments	67	(71)
Estimated annual amortization expense, intangible assets, 2021	2,000
Estimated annual amortization expense, intangible assets, 2022	2,000
Estimated annual amortization expense, intangible assets, 2023	1,900
Estimated annual amortization expense, intangible assets, 2024	1,900
Estimated annual amortization expense, intangible assets, 2025	1,900
Indefinite-lived intangible assets related to in-process R&D acquired in a business combination	1,200	$ 1,300
Medical Devices
Goodwill and Intangible Assets
Impairment of indefinite-lived intangible assets in-process research and development project	55
Impairment of amortizable intangible assets	$ 148
Minimum
Goodwill and Intangible Assets
Amortization period of intangible assets	2 years
Maximum
Goodwill and Intangible Assets
Amortization period of intangible assets	20 years