Intangible Assets, Goodwill, and Acquisitions - Narrative (Details) - USD ($)		1 Months Ended	3 Months Ended	12 Months Ended
	Sep. 20, 2020	Jan. 31, 2021	Jun. 28, 2020	Jan. 03, 2021
Goodwill [Line Items]
Goodwill impairment			$ 0
Developed Technology
Goodwill [Line Items]
Value of intangible assets acquired				$ 26,000,000
Weighted-average useful lives (in years)				10 years
GRAIL, Inc
Goodwill [Line Items]
Business acquisition total consideration	$ 8,000,000,000
Cash payments	3,500,000,000
Business combination, equity Interests Issued and Issuable (in shares)	4,500,000,000
Capital raised	1,000,000,000
Principal amount of notes outstanding	$ 1,000,000,000
Contingent value right, terms	12 years
Business combination, continuation payments	$ 35,000,000
Business combination, threshold of continuation payments	315,000,000
Termination fee	300,000,000
Investment to be made if merger does not occur	$ 300,000,000
GRAIL, Inc | Subsequent Event
Goodwill [Line Items]
Business combination, monthly additional payments		$ 35,000,000
GRAIL, Inc | Payment Rights Of One Billion Each Twelve Years
Goodwill [Line Items]
Contingent payment rights, first percentage	2.50%
Business acquisition, contingent value rights, revenue threshold	$ 1,000,000,000
GRAIL, Inc | Payment Rights Of Above One Billion Each Twelve Years
Goodwill [Line Items]
Business acquisition, contingent value rights, revenue threshold	$ 1,000,000,000
Contingent payment rights, second percentage	9.00%