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Acquisitions, Goodwill, and Acquired Intangible Assets - Additional Information (Details) - USD ($) $ in Millions			12 Months Ended
	Sep. 11, 2018	Apr. 12, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Amortization expense for acquired intangibles			$ 509	$ 565	$ 475
Ring Inc.
Business Acquisition [Line Items]
Acquisitions, net of cash acquired		$ 839
PillPack, Inc.
Business Acquisition [Line Items]
Acquisitions, net of cash acquired	$ 753
Other Acquisitions
Business Acquisition [Line Items]
Aggregate purchase price			1,200	$ 315	$ 57
Acquisitions, in-process research and development intangible asset			$ 1,100