Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Jan. 03, 2021	Dec. 29, 2019	Dec. 30, 2018
Revenue:
Total revenue	$ 3,239	$ 3,543	$ 3,333
Cost of revenue:
Amortization of acquired intangible assets	28	34	35
Total cost of revenue	1,036	1,076	1,033
Gross profit	2,203	2,467	2,300
Operating expense:
Research and development	682	647	623
Selling, general and administrative	941	835	794
Total operating expense	1,623	1,482	1,417
Income from operations	580	985	883
Other income (expense):
Interest income	41	75	44
Interest expense	(49)	(52)	(57)
Other income, net	284	110	24
Total other income, net	276	133	11
Income before income taxes	856	1,118	894
Provision for income taxes	200	128	112
Consolidated net income	656	990	782
Add: Net loss attributable to noncontrolling interests	0	12	44
Net income attributable to Illumina stockholders	$ 656	$ 1,002	$ 826
Earnings per share attributable to Illumina stockholders:
Basic (in dollars per share)	$ 4.48	$ 6.81	$ 5.63
Diluted (in dollars per share)	$ 4.45	$ 6.74	$ 5.56
Shares used in computing earnings per share:
Basic (in shares)	147	147	147
Diluted (in shares)	148	149	149
Product revenue
Revenue:
Total revenue	$ 2,735	$ 2,929	$ 2,749
Cost of revenue:
Cost of revenue	788	802	738
Service and other revenue
Revenue:
Total revenue	504	614	584
Cost of revenue:
Cost of revenue	$ 220	$ 240	$ 260