Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Jan. 03, 2021	Dec. 29, 2019	Dec. 30, 2018
Statement of Comprehensive Income [Abstract]
Consolidated net income	$ 656	$ 990	$ 782
Unrealized (loss) gain on available-for-sale debt securities, net of deferred tax	(3)	6	0
Total consolidated comprehensive income	653	996	782
Add: Comprehensive loss attributable to noncontrolling interests	0	12	44
Comprehensive income attributable to Illumina stockholders	$ 653	$ 1,008	$ 826