Related Parties and Related Commitments and Contingencies - Net Transfer From (to) Parent (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Mar. 28, 2025	Dec. 27, 2024	Sep. 27, 2024	Apr. 03, 2026	Mar. 28, 2025
Related Party Transaction [Line Items]
Net transfers from Western Digital Corporation per Condensed Consolidated Statements of Shareholders’ Equity	$ (1,076)	$ (92)	$ 583
Other assets and liabilities, net transferred from Western Digital Corporation				$ 0	$ 105
Unis Venture transferred from Western Digital Corporation				0	61
Property, plant and equipment, net transferred from Western Digital Corporation				0	27
Tax balances transferred from Western Digital Corporation				0	8
Tax indemnification liability transferred to Western Digital Corporation				0	112
Related Party
Related Party Transaction [Line Items]
Net transfers from Western Digital Corporation per Condensed Consolidated Statements of Shareholders’ Equity				0	(585)
Notes due to Western Digital Corporation				0	(1,223)
Other assets and liabilities, net transferred from Western Digital Corporation				0	(105)
Unis Venture transferred from Western Digital Corporation				0	(61)
Property, plant and equipment, net transferred from Western Digital Corporation				0	(27)
Tax balances transferred from Western Digital Corporation				0	(8)
Accumulated other comprehensive loss transferred from Western Digital Corporation				0	10
Tax indemnification liability transferred to Western Digital Corporation				0	112
Net transfers to Western Digital Corporation per Condensed Consolidated Statements of Cash Flows				$ 0	$ (1,887)