ORGANIZATION AND DESCRIPTION OF BUSINESS (Details) - USD ($) $ in Thousands		6 Months Ended		34 Months Ended
	Jun. 24, 2024	Jun. 30, 2024	Jun. 30, 2023	Jun. 23, 2024	Dec. 31, 2023
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of shares distributed in spin-off (in shares)		31,049,148		0	0
Cash funding received from Illumina		$ 1,244,300	$ 304,000
Cash and cash equivalents.		$ 958,845	$ 230,621		$ 97,287
Illumina, Inc.
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Percent of shares distributed in spin-off	85.50%
Stockholders' Equity Note, Spinoff Transaction, Number Of Shares Distributed	31,000,000.0
Illumina, Inc.
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Cash funding received from Illumina	$ 932,300
Clawback term on disposal funding	15 months
SDG Ops, LLC | Illumina, Inc.
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Percentage ownership prior to spin-off				100.00%
Grail, Inc. | Illumina, Inc.
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Percentage of shares retained after spin-off	14.50%