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Restructuring - Schedule of Restructuring-related Liabilities (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2025	Jun. 24, 2025	Dec. 28, 2024	Dec. 30, 2023
2024 Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 122	$ 122	$ 4,411
2024 Plan \| Cash Restructuring-Related Liabilities Roll-Forward
Restructuring Cost and Reserve [Line Items]
Beginning Balance	6,476		7,312
Restructuring charges	84		3,720	$ 16,829
Payments	(1,407)		(5,247)	(9,731)
Change in estimate	38		691	214
Ending Balance	5,191	5,191	6,476	7,312
2024 Plan \| Lease Termination Costs \| Cash Restructuring-Related Liabilities Roll-Forward
Restructuring Cost and Reserve [Line Items]
Beginning Balance			168
Restructuring charges				168
Payments			(168)
Ending Balance				168
2024 Plan \| Employee Termination Benefit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges	38	38	3,753
2024 Plan \| Employee Termination Benefit Costs \| Cash Restructuring-Related Liabilities Roll-Forward
Restructuring Cost and Reserve [Line Items]
Beginning Balance	6,476		7,144
Restructuring charges			3,062	15,520
Payments	(1,323)		(4,421)	(8,590)
Change in estimate	38		691	214
Ending Balance	5,191	5,191	6,476	7,144
2024 Plan \| Other Cash Restructuring Charges
Restructuring Cost and Reserve [Line Items]
Restructuring charges	84	84	658
2024 Plan \| Other Cash Restructuring Charges \| Cash Restructuring-Related Liabilities Roll-Forward
Restructuring Cost and Reserve [Line Items]
Restructuring charges	84		658	1,141
Payments	(84)		(658)	(1,141)
2023 Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charges			(4,533)
2023 Plan \| Cash Restructuring-Related Liabilities Roll-Forward
Restructuring Cost and Reserve [Line Items]
Beginning Balance	1,627		9,732	26,758	$ 13,608
Restructuring charges				5,491	47,106
Payments	(636)		(3,572)	(22,123)	(33,956)
Change in estimate			(4,533)	(394)
Ending Balance	991	991	1,627	9,732	26,758
2023 Plan \| Other Cash Restructuring Charges \| Cash Restructuring-Related Liabilities Roll-Forward
Restructuring Cost and Reserve [Line Items]
Beginning Balance				344
Restructuring charges				581	1,577
Payments				(925)	(1,233)
Ending Balance					344
2023 Plan \| Real Estate Restructuring \| Lease Termination Costs \| Cash Restructuring-Related Liabilities Roll-Forward
Restructuring Cost and Reserve [Line Items]
Beginning Balance				156
Restructuring charges					12,924
Payments				(21)	(12,768)
Change in estimate				(135)
Ending Balance					156
2023 Plan \| Real Estate Restructuring \| Employee Termination Benefit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges			(2,207)
2023 Plan \| Real Estate Restructuring \| Employee Termination Benefit Costs \| Cash Restructuring-Related Liabilities Roll-Forward
Restructuring Cost and Reserve [Line Items]
Beginning Balance	440		3,266	2,663	1,798
Restructuring charges				2,363	5,678
Payments	(227)		(619)	(1,835)	(4,813)
Change in estimate			(2,207)	75
Ending Balance	213	213	440	3,266	2,663
2023 Plan \| Organizational Restructuring \| Employee Termination Benefit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges			(2,326)
2023 Plan \| Organizational Restructuring \| Employee Termination Benefit Costs \| Cash Restructuring-Related Liabilities Roll-Forward
Restructuring Cost and Reserve [Line Items]
Beginning Balance	1,187		6,466	23,595	11,810
Restructuring charges				2,547	26,927
Payments	(409)		(2,953)	(19,342)	(15,142)
Change in estimate			(2,326)	(334)
Ending Balance	$ 778	$ 778	$ 1,187	$ 6,466	$ 23,595