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Basis of Presentation and Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions		12 Months Ended
	Nov. 04, 2024	Sep. 27, 2025	Sep. 28, 2024	Sep. 30, 2023
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Percentage of shares received by pre-Transaction Treasure shareholders	90.00%
Percentage of shares received by GLT shareholders	10.00%
Research and development expenditures		$ 20	$ 13	$ 15
Share-based compensation expense		19	7	$ 7
Inventory reserves		$ 25	15
Terminal growth rate		2.50%
Impairment charges		$ 0	$ 171
Amortization expense in 2026		45
Amortization expense in 2027		43
Amortization expense in 2028		33
Amortization expense in 2029		27
Amortization expense in 2030		$ 26
Treasure [Member] \| Berry [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Berry's net investment in Treasure after closing of Transaction	0.00%
Minimum [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Discount rates		11.00%
Maximum [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Discount rates		13.00%
Customer Relationships [Member] \| Minimum [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Intangible assets, useful life		10 years
Customer Relationships [Member] \| Maximum [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Intangible assets, useful life		15 years
Trademarks [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Indefinite lived intangible assets		$ 26
Trademarks [Member] \| Maximum [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Intangible assets, useful life		15 years
Other Intangibles [Member] \| Minimum [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Intangible assets, useful life		8 years
Other Intangibles [Member] \| Maximum [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Intangible assets, useful life		20 years
Buildings and Improvements [Member] \| Minimum [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Proprty, plant and equipment, useful life		15 years
Buildings and Improvements [Member] \| Maximum [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Proprty, plant and equipment, useful life		40 years
Machinery, Equipment and Tooling [Member] \| Minimum [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Proprty, plant and equipment, useful life		2 years
Machinery, Equipment and Tooling [Member] \| Maximum [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Proprty, plant and equipment, useful life		20 years
Customer Concentration Risk [Member] \| Revenue Benchmark [Member] \| Customer [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Percentage of net sales		14.00%
Customer Concentration Risk [Member] \| Revenue Benchmark [Member] \| Top Ten Customers [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Abstract]
Percentage of net sales		42.00%