Discontinued Operations and Disposal Groups (Details) - USD ($) $ in Millions	1 Months Ended	6 Months Ended		11 Months Ended	12 Months Ended
	Dec. 29, 2023	Dec. 30, 2022	Jun. 16, 2022	Nov. 14, 2023	Dec. 27, 2024	Feb. 01, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (loss) from continuing operations before income taxes	$ (46.2)	$ (650.3)	$ (811.3)	$ (1,909.1)	$ 614.5
Intangible asset amortization	16.2	318.7	281.8	449.6	80.3
Transaction Services Agreement Revenue					1.0
Minimum | 2018 Program
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Mallinckrodt program expected cost range						$ 100.0
Maximum | 2018 Program
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Mallinckrodt program expected cost range						$ 125.0
Transaction Incentive Plan
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Participant Compensation					13.6
Participant Compensation, Paid After the Next Twelve Months					16.4
Accrued Bonuses					2.7
Initial Purchase Price
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Divestiture of Businesses					925.0
Therakos Divestiture
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Divestiture of Businesses					887.6
Net Assets Divested					125.5
Professional Fees					7.7
Therakos
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (loss) from continuing operations before income taxes	5.1	(79.1)	37.3	(27.4)	66.7
Inventory Step-up Expense	13.0	62.3	0.0	30.1	66.3
Intangible asset amortization	$ 4.6	$ 102.7	$ 35.5	$ 142.7	$ 16.1