Goodwill and Intangible Assets - Goodwill (Details) - USD ($)		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019
Changes in the carrying amount of goodwill
Balance at the beginning of the period		$ 15,604,000,000	$ 15,663,000,000
Foreign currency translation adjustments		512,000,000	(59,000,000)
Additions	[1]	17,008,000,000
Balance at the end of the period		33,124,000,000	$ 15,604,000,000
Accumulated goodwill impairment losses
Accumulated goodwill impairment losses		$ 0

[1] Goodwill additions related to the acquisition of Allergan in the second quarter of 2020 and the acquisition of Luminera in the fourth quarter of 2020 (see Note 5).