Condensed Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 27, 2020	Sep. 29, 2019	Sep. 27, 2020	Sep. 29, 2019
Revenue:
Total revenue	$ 794	$ 907	$ 2,286	$ 2,591
Cost of revenue:
Amortization of acquired intangible assets	7	9	21	28
Total cost of revenue	268	259	713	786
Gross profit	526	648	1,573	1,805
Operating expense:
Research and development	172	151	483	486
Selling, general and administrative	192	189	643	602
Total operating expense	364	340	1,126	1,088
Income from operations	162	308	447	717
Other income (expense):
Interest income	5	16	26	59
Interest expense	(11)	(11)	(33)	(41)
Other income (expense), net	59	(43)	117	114
Total other income (expense), net	53	(38)	110	132
Income before income taxes	215	270	557	849
Provision for income taxes	36	36	158	98
Consolidated net income	179	234	399	751
Add: Net loss attributable to noncontrolling interests	0		0	12
Net income attributable to Illumina stockholders	$ 179	$ 234	$ 399	$ 763
Earnings per share attributable to Illumina stockholders:
Basic (in dollars per share)	$ 1.22	$ 1.59	$ 2.72	$ 5.19
Diluted (in dollars per share)	$ 1.21	$ 1.58	$ 2.70	$ 5.13
Shares used in computing earnings per share:
Basic (in shares)	146	147	147	147
Diluted (in shares)	148	148	148	149
Product revenue
Revenue:
Total revenue	$ 676	$ 746	$ 1,904	$ 2,117
Cost of revenue:
Cost of revenue	209	195	535	573
Service and other revenue
Revenue:
Total revenue	118	161	382	474
Cost of revenue:
Cost of revenue	$ 52	$ 55	$ 157	$ 185