Business Combination and Divestitures - Schedule of Estimated Fair Values (Details) - USD ($) $ in Millions	Jul. 31, 2025	Sep. 26, 2025	Dec. 27, 2024
Business Acquisition [Line Items]
Goodwill		$ 7.3	$ 0.0
Mallinckrodt & Endo Merger
Business Acquisition [Line Items]
Total consideration transferred	$ 1,884.5
Cash and cash equivalents	437.6
Restricted cash and cash equivalents	93.4
Accounts receivable, net	357.7
Inventories	885.7
Prepaid expenses and other current assets	81.2
Income taxes receivable	21.3
Property, plant and equipment, net	402.4
Inventories, long-term	502.6
Operating lease assets	36.8
Intangible assets, net	2,215.0
Deferred income tax assets	144.4
Other assets	20.4
Total assets, excluding goodwill	5,198.5
Current maturities of long-term debt	15.0
Accounts payable	91.5
Accrued payroll and payroll-related costs	63.2
Accrued interest	25.3
Accrued and other current liabilities	314.4
Long-term debt	2,545.0
Operating lease liabilities	33.2
Other income tax liabilities	139.4
Other liabilities	94.3
Net assets acquired	1,877.2
Goodwill	$ 7.3