Fresh-Start Accounting - Reorganization Adjustments (Details) - USD ($) $ / shares in Units, $ in Millions			1 Months Ended	6 Months Ended		11 Months Ended	12 Months Ended
	Nov. 14, 2023	Jun. 16, 2022	Dec. 29, 2023	Dec. 30, 2022	Jun. 16, 2022	Nov. 14, 2023	Dec. 27, 2024	Jun. 16, 2023	Dec. 31, 2021
Reorganization, Chapter 11 [Line Items]
Cash and cash equivalents	$ 186.7	$ 297.9	$ 262.7	$ 409.5	$ 297.9	$ 186.7	$ 382.6
Debt instrument, face amount			1,647.8				865.6
Issuance of external debt		650.0	0.0	0.0	650.0	380.0	0.0
Opioid-Related Settlement, Emergence Payment		447.4			447.4
Opioid-Related Settlement, Gross Amount of Deferred Payment		1,275.0			1,275.0
Stock Issued During Period, Value, New Issues					2,189.7	1,169.7
Adjustments to Additional Paid in Capital, Warrant Issued					(13.9)	(25.1)
Shareholders' equity	$ 1,194.8	2,203.6	$ 1,160.2	1,613.7	2,203.6	1,194.8	$ 1,645.8		$ 313.4
Adjustments to Retained Deficit, Prepaid Success Fee		(10.9)			(10.9)
Cancellation of Predecessor equity					(0.5)	$ 9.2
Change in Accounting Policy, Fresh-Start		$ 20.3			$ 20.3
Operating Lease, Weighted Average Discount Rate, Percent			8.10%				6.50%
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 99.36	$ 103.40			$ 103.40	$ 99.36
Debtor Reorganization Items, Gain (Loss) on Settlement of Other Claims, Net			$ 0.0	0.0	$ 5.4	$ 1,139.5
Debtor Reorganization Items, Write-off of Debt Issuance Costs and Debt Discounts			0.0	0.0	0.0	21.2
Acthar Gel-Related Settlement, total obligation		$ 260.0	236.1		260.0		$ 214.7
Acthar Gel-Related Settlement			128.5				126.5
Cash Paid, Reorganization items			0.8	18.4	304.1	$ 22.6
Warrants and Rights Outstanding, Term	4 years					4 years
Ordinary Shares
Reorganization, Chapter 11 [Line Items]
Stock Issued During Period, Value, New Issues					0.1	$ 0.2
Shareholders' equity	$ 0.2	0.1	0.2	0.1	0.1	0.2	$ 0.2		$ 18.9
Cancellation of Predecessor equity					(18.9)	(0.1)
Successor
Reorganization, Chapter 11 [Line Items]
Common Stock, Shares, Outstanding							19,696,335
StrataGraft PRV
Reorganization, Chapter 11 [Line Items]
Other Indefinite-lived Intangible Assets		100.0			100.0
Opioid Claimant Trust [Member]
Reorganization, Chapter 11 [Line Items]
Opioid-related Settlement		1,725.0			1,725.0
Acthar Gel-Related Settlement
Reorganization, Chapter 11 [Line Items]
Debtor Reorganization Items, Gain (Loss) on Settlement of Other Claims, Net						145.0
Opioid-related litigation settlement liability
Reorganization, Chapter 11 [Line Items]
Debtor Reorganization Items, Gain (Loss) on Settlement of Other Claims, Net						598.4
Accretion of Debt Discount
Reorganization, Chapter 11 [Line Items]
Debtor Reorganization Items, Gain (Loss) on Settlement of Other Claims, Net						377.6
Receivables Financing Facility
Reorganization, Chapter 11 [Line Items]
Debt instrument, face amount		200.0			200.0
Debt Issuance Costs, Gross	1.7					1.7
Long-Term Debt	98.7					98.7
Ten Point Zero Percent First Lien Notes [Member]
Reorganization, Chapter 11 [Line Items]
Debt instrument, face amount		495.0			495.0
Eleven Point Five Percent First Lien Senior Secured Notes
Reorganization, Chapter 11 [Line Items]
Debtor Reorganization Items, Write-off of Debt Issuance Costs and Debt Discounts						18.5
2017 Replacement Term Loan
Reorganization, Chapter 11 [Line Items]
Debt instrument, face amount		1,392.9			1,392.9
2018 Replacement Term Loan
Reorganization, Chapter 11 [Line Items]
Debt instrument, face amount		369.7			369.7
Debtor-in-Possession Financing
Reorganization, Chapter 11 [Line Items]
Debt instrument, face amount	280.0					280.0
First-Out Takeback Term Loan Due November 2028
Reorganization, Chapter 11 [Line Items]
Debt instrument, face amount	229.4					229.4
Second-Out Takeback Term Loan Due November 2028
Reorganization, Chapter 11 [Line Items]
Debt instrument, face amount	642.0					642.0
Fourteen Point Seven Five Percent Second-Out Takeback Notes
Reorganization, Chapter 11 [Line Items]
Debt instrument, face amount	778.6					778.6
Ten Point Zero Percent Second Lien Notes (Existing Notes)
Reorganization, Chapter 11 [Line Items]
Debt instrument, face amount		322.9			322.9
Takeback Term Loans
Reorganization, Chapter 11 [Line Items]
Debt instrument, face amount	871.4					871.4
Reorganization, Chapter 11, Plan Effect Adjustment
Reorganization, Chapter 11 [Line Items]
Proceeds from Debt, Net of Issuance Costs		637.0
Payment for Debt Extinguishment or Debt Prepayment Cost		900.0
Upfront Payment of the Opioid-Related Litigation Settlement		(447.4)
Upfront Payment of the Acthar Gel-Related Settlement		(17.8)
Payment of Administrative, Priority and Trade Claims		(26.2)
Payment of Professional Fees	(19.4)	43.5
Payment to Fund Professional Fees Escrow	24.0	(89.0)
Payment of General Unsecured Claims		(135.0)
Payment of Noteholder Consent Fees		(19.3)
Payments for Other Fees	33.3	(53.5)
Payment of cash sweep	50.6
Reorganization Adjustments, Cashed Used	127.3	(1,731.7)
Cash and cash equivalents	(127.3)	(1,094.7)			(1,094.7)	(127.3)		$ (1,094.7)
Restricted Cash	24.0	89.0			89.0	24.0
Prepaid Expense, Reorganization Adjustment		10.9
Other Assets, Reorganization Adjustment	2.4
Payments for Cure and Standard, Administrative and Priority Payments		25.2			25.2
Payables due to Professional Advisor Success Fees		14.6			14.6
Acthar Gel-Related Settlement, Current	21.4	16.5			16.5	21.4
Opioid-Related Litigation Settlement liability		200.0			200.0
Opioid-Related Litigation Settlement		304.3			304.3
Contingent consideration		(41.8)			(41.8)
Liabilities Subject to Compromise	4,932.1	6,402.7			6,402.7	4,932.1
Liabilities, Reinstated	(236.2)	(59.8)			(59.8)	(236.2)
Stock Issued During Period, Value, New Issues	(1,169.7)	(2,189.7)
Adjustments to Additional Paid in Capital, Warrant Issued	(25.1)	(13.9)
Issuance of Takeback 2L Notes		(190.2)			(190.2)
Cash payments to settle amounts per the Plan		(601.3)			(601.3)
Total consideration provided to settle amounts per the Plan	(2,729.9)	(5,399.2)			(5,399.2)	(2,729.9)
Gain on settlement of liabilities subject to compromise	1,966.0	943.7	0.0	0.0	(943.7)	(1,966.0)
Additional Paid in Capital, Common Stock	1,169.5	2,189.6			2,189.6	1,169.5
Shareholders' equity	$ 3,682.2	$ 2,927.2			$ 2,927.2	$ 3,682.2
Share Price	$ 60.28	$ 18.50			$ 18.50	$ 60.28
Volatility, Black Scholes Model, Warrants	65.00%	62.28%			62.28%	65.00%
Adjustment to Retained Deficit, Professional, Success and Exit Fees	$ (24.0)	$ (91.6)			$ (91.6)	$ (24.0)
Adjustments to Retained Deficit, Prepaid Insurance	(20.0)	(9.2)			(9.2)	(20.0)
Adjustments to Retained Deficit, Fair Value of First-Out Takeback Term Loans and Related Embedded Derivative	(21.2)					(21.2)
Adjustment to Retained Deficit, Severance Accrual		(5.7)			(5.7)
Adjustment to Retained Deficit, Income Tax Expense on Plan Adjustments	585.9	(102.7)			(102.7)	585.9
Cancellation of Predecessor equity	2,199.9	4,002.3
Reorganization Adjustments to Retained Deficit	$ 4,686.6	$ 4,725.9			$ 4,725.9	$ 4,686.6
Risk-Free Interest Rate, Black Scholes Model, Warrants	4.49%	3.34%			3.34%	4.49%
Derivative Liability, Current	$ 7.6					$ 7.6
Derivative Liability, Noncurrent	7.5					7.5
Acthar Gel-Related Settlement	214.7	$ 63.2			$ 63.2	214.7
Ordinary shares, shares issued (in shares)		13,170,932			13,170,932
Reorganization, Chapter 11, Plan Effect Adjustment | Ordinary Shares
Reorganization, Chapter 11 [Line Items]
Stock Issued During Period, Value, New Issues	0.2	$ 0.1
Reorganization, Chapter 11, Plan Effect Adjustment | StrataGraft PRV | General Unsecured Claims Trust
Reorganization, Chapter 11 [Line Items]
Contingent consideration		35.0			$ 35.0
Reorganization, Chapter 11, Plan Effect Adjustment | StrataGraft CVR
Reorganization, Chapter 11 [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Contingent Liability	14.9	6.8			6.8	14.9
Reorganization, Chapter 11, Plan Effect Adjustment | Other current liabilities
Reorganization, Chapter 11 [Line Items]
Restructuring Reserve		5.7			5.7
Reinstatement of various successor obligations from LSTC		15.4			15.4
Accrued and Other Current Liabilities, Reorganization Adjustment		29.7			29.7
Accrued and Other Current Liabilities, Reorganization Adjustment		50.8			50.8
Asbestos-related defense cost accrual		16.8			16.8
Reorganization, Chapter 11, Plan Effect Adjustment | Accounts Payable
Reorganization, Chapter 11 [Line Items]
Liabilities Subject to Compromise		(17.7)			(17.7)
Liabilities, Reinstated		(0.1)			(0.1)
Reorganization, Chapter 11, Plan Effect Adjustment | Interest Payable, Current
Reorganization, Chapter 11 [Line Items]
Liabilities Subject to Compromise	(158.8)	(35.2)			(35.2)	(158.8)
Reorganization, Chapter 11, Plan Effect Adjustment | Long-term Debt [Member]
Reorganization, Chapter 11 [Line Items]
Liabilities Subject to Compromise	(3,512.1)	(3,746.2)			(3,746.2)	(3,512.1)
Liabilities, Reinstated	(1,535.1)	(1,778.3)			(1,778.3)	(1,535.1)
Reorganization, Chapter 11, Plan Effect Adjustment | Accrued Environmental Loss Contingencies
Reorganization, Chapter 11 [Line Items]
Liabilities Subject to Compromise		(67.2)			(67.2)
Reorganization, Chapter 11, Plan Effect Adjustment | Acthar Gel-Related Settlement
Reorganization, Chapter 11 [Line Items]
Liabilities Subject to Compromise	(236.1)	(630.0)			(630.0)	(236.1)
Liabilities, Reinstated		(79.7)			(79.7)
Reorganization, Chapter 11, Plan Effect Adjustment | Opioid-related litigation settlement liability
Reorganization, Chapter 11 [Line Items]
Liabilities Subject to Compromise	(1,025.0)	(1,722.4)			(1,722.4)	(1,025.0)
Liabilities, Reinstated		(504.3)			(504.3)
Reorganization, Chapter 11, Plan Effect Adjustment | Other Liabilities
Reorganization, Chapter 11 [Line Items]
Liabilities Subject to Compromise	(0.1)	(151.6)			(151.6)	(0.1)
Liabilities, Reinstated	(236.1)	(27.3)			(27.3)	(236.1)
Reorganization, Chapter 11, Plan Effect Adjustment | Liability, Defined Benefit Plan, Noncurrent
Reorganization, Chapter 11 [Line Items]
Liabilities Subject to Compromise		(32.4)			(32.4)
Liabilities, Reinstated	(0.1)	(32.4)			(32.4)	(0.1)
Reorganization, Chapter 11, Plan Effect Adjustment | Medicaid Lawsuit [Member]
Reorganization, Chapter 11 [Line Items]
Acthar Gel-Related Settlement, Gross Amount of Deferred Payments		$ 245.0			$ 245.0
Discount Rate, Present Value of Future Cash Flows		27.80%			27.80%
Acthar Gel-Related Settlement, Emergence Payment, net of Interest		$ 17.8			$ 17.8
Reorganization, Chapter 11, Plan Effect Adjustment | Opioid Claimant Trust [Member]
Reorganization, Chapter 11 [Line Items]
Opioid-related Settlement		$ 1,725.0			$ 1,725.0
Reorganization, Chapter 11, Plan Effect Adjustment | Opioid-related litigation settlement liability
Reorganization, Chapter 11 [Line Items]
Discount Rate, Present Value of Future Cash Flows		27.80%			27.80%
Reorganization, Chapter 11, Plan Effect Adjustment | Insurance Policy Write-off
Reorganization, Chapter 11 [Line Items]
Prepaid Expense, Reorganization Adjustment	17.2
Reorganization, Chapter 11, Plan Effect Adjustment | Directors Compensation Write-off
Reorganization, Chapter 11 [Line Items]
Prepaid Expense, Reorganization Adjustment	0.4
Reorganization, Chapter 11, Plan Effect Adjustment | Receivables Financing Facility
Reorganization, Chapter 11 [Line Items]
Payment for Debt Extinguishment or Debt Prepayment Cost		$ (900.0)
Payments of Debt Issuance Costs		2.6
Other Assets, Reorganization Adjustment		6.5
Reorganization, Chapter 11, Plan Effect Adjustment | Ten Point Zero Percent Second Lien Notes due 2029
Reorganization, Chapter 11 [Line Items]
Debt instrument, face amount		375.0			$ 375.0
Reorganization Plan Adjustment		(184.8)			(184.8)
Reorganization, Chapter 11, Plan Effect Adjustment | Ten Point Zero Percent First Lien Notes [Member]
Reorganization, Chapter 11 [Line Items]
Debt instrument, face amount		495.0			495.0
Debt Issuance Costs, Gross		5.1			5.1
Reorganization, Chapter 11, Plan Effect Adjustment | Eleven Point Five Percent First Lien Senior Secured Notes
Reorganization, Chapter 11 [Line Items]
Issuance of external debt		650.0
Reorganization, Chapter 11, Plan Effect Adjustment | Eleven Point Five Percent First Lien Senior Secured Notes | Original Issuance Discount
Reorganization, Chapter 11 [Line Items]
Debt Issuance Costs, Gross		13.0			13.0
Reorganization, Chapter 11, Plan Effect Adjustment | Eleven Point Five Percent First Lien Senior Secured Notes | Deferred Debt Issuance Costs
Reorganization, Chapter 11 [Line Items]
Debt Issuance Costs, Gross		9.7			9.7
Reorganization, Chapter 11, Plan Effect Adjustment | 2017 Replacement Term Loan
Reorganization, Chapter 11 [Line Items]
Debt instrument, face amount		1,392.9			1,392.9
Reorganization Plan Adjustment		(169.4)			(169.4)
Reorganization, Chapter 11, Plan Effect Adjustment | 2018 Replacement Term Loan
Reorganization, Chapter 11 [Line Items]
Debt, Current		34.7			34.7
Debt instrument, face amount		369.7			369.7
Reorganization Plan Adjustment		(42.2)			(42.2)
Reorganization, Chapter 11, Plan Effect Adjustment | Ten Point Zero Percent Second Lien Notes (New 2L Notes)
Reorganization, Chapter 11 [Line Items]
Reorganization Plan Adjustment		(95.7)			(95.7)
Reorganization, Chapter 11, Plan Effect Adjustment | Debt
Reorganization, Chapter 11 [Line Items]
Reorganization Plan Adjustment		(492.1)			(492.1)
Reorganization, Chapter 11, Plan Effect Adjustment | First-Out Takeback Term Loan Due November 2028
Reorganization, Chapter 11 [Line Items]
Reorganization Plan Adjustment	15.0					15.0
Reorganization, Chapter 11, Plan Effect Adjustment | Second-Out Takeback Term Loan Due November 2028
Reorganization, Chapter 11 [Line Items]
Reorganization Plan Adjustment	46.3					46.3
Reorganization, Chapter 11, Plan Effect Adjustment | Fourteen Point Seven Five Percent Second-Out Takeback Notes
Reorganization, Chapter 11 [Line Items]
Reorganization Plan Adjustment	59.3					59.3
Reorganization, Chapter 11, Plan Effect Adjustment | Secured Debt
Reorganization, Chapter 11 [Line Items]
Reorganization Plan Adjustment	120.6					120.6
Reorganization, Chapter 11, Plan Effect Adjustment | Ten Point Zero Percent Second Lien Notes (Existing Notes)
Reorganization, Chapter 11 [Line Items]
Debt instrument, face amount		322.9			322.9
Reorganization, Chapter11, Post Adjustment, Successor
Reorganization, Chapter 11 [Line Items]
Cash and cash equivalents	186.8	297.9			297.9	186.8
Acthar Gel-Related Settlement, Current	21.4	16.5			16.5	21.4
Opioid-Related Litigation Settlement liability		200.0			200.0
Opioid-Related Litigation Settlement		304.3			304.3
Liabilities Subject to Compromise	0.0	0.0			0.0	0.0
Shareholders' equity	1,194.8	2,203.6			2,203.6	1,194.8
Acthar Gel-Related Settlement	126.1	63.2			63.2	126.1
Preferred Stock, Value, Outstanding		0.0			0.0
Reorganization, Chapter 11, Fresh-Start Adjustment
Reorganization, Chapter 11 [Line Items]
Cash and cash equivalents	0.0	0.0			0.0	0.0
Acthar Gel-Related Settlement, Current	0.0	0.0			0.0	0.0
Opioid-Related Litigation Settlement liability		0.0			0.0
Opioid-Related Litigation Settlement		0.0			0.0
Liabilities Subject to Compromise	0.0	0.0			0.0	0.0
Shareholders' equity	$ (1,243.6)	(772.5)			(772.5)	$ (1,243.6)
Fresh-Start Adjustment, Spare Parts		3.9			3.9
Fresh-Start Adjustments, Debt Issuance Costs		1.1			1.1
Fresh-Start Adjustments, Income Tax Receivables		$ 0.9			$ 0.9
Operating Lease, Weighted Average Discount Rate, Percent	8.10%	11.83%			11.83%	8.10%
Fresh-Start Adjustments, Right-of-Use Assets	$ 12.5	$ 1.6			$ 1.6	$ 12.5
Fresh-Start Adjustments, Asbestos-Related Defense Costs, Current		6.1			6.1
Fresh-Start Adjustments, Asbestos-Related Defense Costs, Non-Current		16.7			16.7
Fresh-Start Adjustments, Lease Liabilities		6.9			6.9
Fresh-Start Adjustments, Unamortized Debt Issuance Costs		5.1			5.1
Fresh-Start Adjustments, Debt, Fair Value		23.5			23.5
Adjustment to Retained Deficit, Inventory	257.6	851.8			851.8	257.6
Adjustment to Retained Deficit, Property, Plant and Equipment	(150.2)	(299.2)			(299.2)	(150.2)
Fresh-Start Adjustments, Intangible assets, net	(1,633.7)	(2,014.4)			(2,014.4)	(1,633.7)
Fresh-Start Adjustments, Acthar Gel-Related Settlement	88.6					88.6
Adjustments to Retained Deficit, Current Asset Held for Sale		100.0			100.0
Adjustment to Retained Deficit, Debt		18.4			18.4
Adjustment to Retained Deficit, Other Assets and Liabilities	(15.0)	(11.2)			(11.2)	(15.0)
Reorganization Items, net, Loss on Fresh-Start Adjustments	(1,452.7)	(1,354.6)	$ 0.0	$ 0.0	1,354.6	1,452.7
Fresh-Start Adjustments, Accumulated Other Comprehensive Income	11.1	(9.9)			(9.9)	11.1
Fresh-Start Adjustments, Income Tax Benefit	209.1	582.1			582.1	209.1
Fresh-Start Adjustment, Accumulated Retained Deficit	(1,232.5)	(782.4)			(782.4)	(1,232.5)
Fresh-Start Adjustment, Prepaid Income Taxes		54.0			54.0
Fresh-Start Adjustments, Lease Liabilities, Current	0.1					0.1
Fresh-Start Adjustments, Lease Liabilities, Noncurrent	12.7					12.7
Acthar Gel-Related Settlement	$ (88.6)	0.0			0.0	$ (88.6)
Preferred Stock, Value, Outstanding		0.0			0.0
Reorganization, Chapter 11, Fresh-Start Adjustment | Acthar Gel-Related Settlement | Minimum
Reorganization, Chapter 11 [Line Items]
Discount Rate, Present Value of Future Cash Flows	13.30%					13.30%
Reorganization, Chapter 11, Fresh-Start Adjustment | Indemnification Receivable, Current
Reorganization, Chapter 11 [Line Items]
Change in Accounting Policy, Fresh-Start		$ 4.3			$ 4.3
Reorganization, Chapter 11, Fresh-Start Adjustment | Finite-Lived Intangible Assets | Minimum
Reorganization, Chapter 11 [Line Items]
Discount Rate, Present Value of Future Cash Flows	13.50%	13.00%			13.00%	13.50%
Reorganization, Chapter 11, Fresh-Start Adjustment | Finite-Lived Intangible Assets | Maximum
Reorganization, Chapter 11 [Line Items]
Discount Rate, Present Value of Future Cash Flows	52.50%	15.00%			15.00%	52.50%
Reorganization, Chapter 11, Fresh-Start Adjustment | Indemnification Receivable, Non-Current
Reorganization, Chapter 11 [Line Items]
Change in Accounting Policy, Fresh-Start		$ 16.0			$ 16.0
Reorganization, Chapter 11, Fresh-Start Adjustment | Accumulated Other Comprehensive (Loss) Income
Reorganization, Chapter 11 [Line Items]
Fresh-Start Adjustments, Asbestos-Related Defense Costs, Current		8.1			8.1
Fresh-Start Adjustments, AOCI, Income Tax Effects	$ 2.5	0.3			0.3	$ 2.5
Fresh-Start Adjustments, AOCI, Pension Benefits	10.0					10.0
Fresh-Start Adjustments, AOCI, CTA	2.1	2.1			2.1	2.1
Fresh-Start Adjustments, AOCI, Derivatives	5.7					5.7
Fresh-Start Adjustments, AOCI, Income Tax Benefit	0.0					0.0
Reorganization, Chapter 11, Predecessor, before Adjustment
Reorganization, Chapter 11 [Line Items]
Cash and cash equivalents	314.1	1,392.6			1,392.6	314.1
Acthar Gel-Related Settlement, Current	0.0	0.0			0.0	0.0
Opioid-Related Litigation Settlement liability		0.0			0.0
Opioid-Related Litigation Settlement		0.0			0.0
Liabilities Subject to Compromise	(4,932.1)	(6,402.7)			(6,402.7)	(4,932.1)
Shareholders' equity	$ (1,243.8)	$ 48.9			$ 48.9	$ (1,243.8)
Operating Lease, Weighted Average Discount Rate, Percent	13.20%	8.85%			8.85%	13.20%
Acthar Gel-Related Settlement	$ 0.0	$ 0.0			$ 0.0	$ 0.0
Preferred Stock, Value, Outstanding		$ 0.0			$ 0.0