Related Parties and Related Commitments and Contingencies - Net Transfer From (to) Parent (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Dec. 27, 2024	Sep. 27, 2024	Jan. 02, 2026	Dec. 27, 2024
Related Party Transaction [Line Items]
Net transfers from Western Digital Corporation per Condensed Consolidated Statements of Shareholders’ Equity	$ (92)	$ 583
Other assets and liabilities, net transferred from Western Digital Corporation			$ 0	$ 44
Property, plant and equipment, net transferred from Western Digital Corporation			0	25
Tax balances transferred from Western Digital Corporation			0	(14)
Related Party
Related Party Transaction [Line Items]
Net transfers from Western Digital Corporation per Condensed Consolidated Statements of Shareholders’ Equity			0	491
Notes due to (from) Western Digital Corporation			0	(673)
Other assets and liabilities, net transferred from Western Digital Corporation			0	(44)
Property, plant and equipment, net transferred from Western Digital Corporation			0	(25)
Tax balances transferred from Western Digital Corporation			0	14
Accumulated other comprehensive loss transferred from Western Digital Corporation			0	6
Net transfers to Western Digital Corporation per Condensed Consolidated Statements of Cash Flows			$ 0	$ (231)