Fresh-Start Accounting - Reorganization Adjustments (Details) - USD ($) $ / shares in Units, $ in Millions		6 Months Ended		12 Months Ended
	Jun. 16, 2022	Dec. 30, 2022	Jun. 16, 2022	Dec. 31, 2021	Dec. 25, 2020	Jul. 01, 2022	Dec. 27, 2019
Reorganization, Chapter 11 [Line Items]
Cash and cash equivalents	$ 297.9	$ 409.5	$ 297.9	$ 1,345.0	$ 1,070.6
Debt instrument, face amount		3,534.1
Issuance of external debt	650.0	0.0	650.0	0.0	0.0
Acthar Gel-Related Settlement, Current	260.0		260.0
Opioid-Related Settlement, Emergence Payment	447.4		447.4
Opioid-Related Settlement, Gross Amount of Deferred Payment	1,275.0		1,275.0
Opioid-Related Litigation Settlement liability, Current		200.0		0.0
Opioid-Related Litigation Settlement liability, Non-current		379.9		0.0
Liabilities Subject to Compromise		0.0		(6,397.7)
Stock Issued During Period, Value, New Issues			2,189.7
Adjustments to Additional Paid in Capital, Warrant Issued			(13.9)
Shareholders' equity	2,203.6	$ 1,613.7	2,203.6	$ 313.4	1,019.2		$ 1,940.7
Share Price						$ 24.40
Adjustments to Retained Deficit, Prepaid Success Fee	$ (10.9)		(10.9)
Cancellation of Predecessor equity			$ (0.5)
Operating Lease, Weighted Average Discount Rate, Percent		11.90%		4.40%
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 103.40		$ 103.40
Ordinary Shares
Reorganization, Chapter 11 [Line Items]
Stock Issued During Period, Value, New Issues			$ 0.1
Shareholders' equity	$ 0.1	$ 0.1	0.1	$ 18.9	18.8		$ 18.7
Cancellation of Predecessor equity			(18.9)
StrataGraft PRV
Reorganization, Chapter 11 [Line Items]
Other Indefinite-lived Intangible Assets	100.0		100.0
Long-term Debt [Member]
Reorganization, Chapter 11 [Line Items]
Liabilities Subject to Compromise		0.0		(3,750.8)
Opioid Claimant Trust [Member]
Reorganization, Chapter 11 [Line Items]
Opioid-related Settlement	1,725.0		1,725.0
Receivables Financing Facility
Reorganization, Chapter 11 [Line Items]
Debt instrument, face amount	200.0		200.0
Ten Point Zero Percent Second Lien Notes due 2029
Reorganization, Chapter 11 [Line Items]
Debt instrument, face amount		328.3
Ten Point Zero Percent First Lien Notes [Member]
Reorganization, Chapter 11 [Line Items]
Debt instrument, face amount	495.0	495.0	495.0
Eleven Point Five Percent First Lien Senior Secured Notes
Reorganization, Chapter 11 [Line Items]
Debt instrument, face amount		650.0
2017 Replacement Term Loan
Reorganization, Chapter 11 [Line Items]
Debt instrument, face amount	1,392.9	1,374.1	1,392.9
2018 Replacement Term Loan
Reorganization, Chapter 11 [Line Items]
Debt instrument, face amount	369.7	364.8	369.7
Ten Point Zero Percent Second Lien Notes (New 2L Notes)
Reorganization, Chapter 11 [Line Items]
Debt instrument, face amount	322.9	321.9	322.9
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	(43.5)
Payment to Fund Professional Fees Escrow	(89.0)
Payment of General Unsecured Claims	(135.0)
Payment of Noteholder Consent Fees	(19.3)
Payments for Other Fees	(53.5)
Reorganization Adjustments, Cashed Used	(1,731.7)
Cash and cash equivalents	(1,094.7)		(1,094.7)
Restricted Cash	89.0		89.0
Prepaid Expense, Reorganization Adjustment	10.9
Other Assets, Reorganization Adjustment	6.5
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	16.5		16.5
Acthar Gel-Related Settlement, Non-current	63.2		63.2
Opioid-Related Litigation Settlement liability, Current	200.0		200.0
Opioid-Related Litigation Settlement liability, Non-current	304.3		304.3
Contingent consideration	(41.8)		(41.8)
Liabilities Subject to Compromise	6,402.7		6,402.7
Liabilities, Reinstated	(59.8)		(59.8)
Stock Issued During Period, Value, New Issues	(2,189.7)
Adjustments to Additional Paid in Capital, Warrant Issued	(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	(5,399.2)		(5,399.2)
Gain on settlement of liabilities subject to compromise	943.7	0.0	(943.7)	0.0	0.0
Additional Paid in Capital, Common Stock	2,189.6		2,189.6
Shareholders' equity	$ 2,927.2		$ 2,927.2
Share Price	$ 18.50		$ 18.50
Volatility, Black Scholes Model, Warrants	62.28%		62.28%
Adjustment to Retained Deficit, Professional, Success and Exit Fees	$ (91.6)		$ (91.6)
Adjustments to Retained Deficit, Prepaid Insurance	(9.2)		(9.2)
Adjustment to Retained Deficit, Severance Accrual	(5.7)		(5.7)
Adjustment to Retained Deficit, Income Tax Expense on Plan Adjustments	(102.7)		(102.7)
Cancellation of Predecessor equity	4,002.3
Reorganization Adjustments to Retained Deficit	$ 4,725.9		$ 4,725.9
Risk-Free Interest Rate, Black Scholes Model, Warrants	3.34%		3.34%
Reorganization, Chapter 11, Plan Effect Adjustment | Ordinary Shares
Reorganization, Chapter 11 [Line Items]
Stock Issued During Period, Value, New Issues	$ 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	6.8		6.8
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
Success fees for professionals	29.7		29.7
Accrued and Other Current Liabilities, Reorganization Adjustment	50.8		50.8
Reorganization, Chapter 11, Plan Effect Adjustment | Other Noncurrent Liabilities
Reorganization, Chapter 11 [Line Items]
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	(35.2)		(35.2)
Reorganization, Chapter 11, Plan Effect Adjustment | Long-term Debt [Member]
Reorganization, Chapter 11 [Line Items]
Liabilities Subject to Compromise	(3,746.2)		(3,746.2)
Liabilities, Reinstated	(1,778.3)		(1,778.3)
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	(630.0)		(630.0)
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	(1,722.4)		(1,722.4)
Liabilities, Reinstated	(504.3)		(504.3)
Reorganization, Chapter 11, Plan Effect Adjustment | Other Liabilities
Reorganization, Chapter 11 [Line Items]
Liabilities Subject to Compromise	(151.6)		(151.6)
Liabilities, Reinstated	(27.3)		(27.3)
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	(32.4)		(32.4)
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
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 | Acthar Gel-Related Settlement
Reorganization, Chapter 11 [Line Items]
Discount Rate, Present Value of Future Cash Flows	27.80%		27.80%
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 | Receivables Financing Facility
Reorganization, Chapter 11 [Line Items]
Payments of Debt Issuance Costs	$ 2.6
Reorganization, Chapter 11, Plan Effect Adjustment | 2017 and 2018 Replacement Term Loan
Reorganization, Chapter 11 [Line Items]
Debt, Current	34.7		$ 34.7
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 Issuance Costs, Gross	5.1		5.1
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 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, Chapter11, Post Adjustment, Successor
Reorganization, Chapter 11 [Line Items]
Cash and cash equivalents	297.9		297.9
Acthar Gel-Related Settlement, Current	16.5		16.5
Acthar Gel-Related Settlement, Non-current	63.2		63.2
Opioid-Related Litigation Settlement liability, Current	200.0		200.0
Opioid-Related Litigation Settlement liability, Non-current	304.3		304.3
Liabilities Subject to Compromise	0.0		0.0
Shareholders' equity	2,203.6		2,203.6
Reorganization, Chapter 11, Fresh-Start Adjustment
Reorganization, Chapter 11 [Line Items]
Cash and cash equivalents	0.0		0.0
Acthar Gel-Related Settlement, Current	0.0		0.0
Acthar Gel-Related Settlement, Non-current	0.0		0.0
Opioid-Related Litigation Settlement liability, Current	0.0		0.0
Opioid-Related Litigation Settlement liability, Non-current	0.0		0.0
Liabilities Subject to Compromise	0.0		0.0
Shareholders' equity	(772.5)		(772.5)
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	11.83%		11.83%
Fresh-Start Adjustments, Right-of-Use Assets	$ 1.6		$ 1.6
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	851.8		851.8
Adjustment to Retained Deficit, Property, Plant and Equipment	(299.2)		(299.2)
Fresh-Start Adjustments, Intangible assets, net	(2,014.4)		(2,014.4)
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	(11.2)		(11.2)
Reorganization Items, net, Loss on Fresh-Start Adjustments	(1,354.6)	$ 0.0	1,354.6	$ 0.0	$ 0.0
Fresh-Start Adjustments, Accumulated Other Comprehensive Income	(9.9)		(9.9)
Fresh-Start Adjustments, Income Tax Benefit	582.1		582.1
Fresh-Start Adjustment, Accumulated Retained Deficit	(782.4)		(782.4)
Fresh-Start Adjustment, Prepaid Income Taxes	54.0		54.0
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	13.00%		13.00%
Reorganization, Chapter 11, Fresh-Start Adjustment | Finite-Lived Intangible Assets | Maximum
Reorganization, Chapter 11 [Line Items]
Discount Rate, Present Value of Future Cash Flows	15.00%		15.00%
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, AOCI, Income Tax Effects	0.3		0.3
Fresh-Start Adjustments, AOCI, Pension Benefits	8.1		8.1
Fresh-Start Adjustments, AOCI, CTA	2.1		2.1
Reorganization, Chapter 11, Predecessor, before Adjustment
Reorganization, Chapter 11 [Line Items]
Cash and cash equivalents	1,392.6		1,392.6
Acthar Gel-Related Settlement, Current	0.0		0.0
Acthar Gel-Related Settlement, Non-current	0.0		0.0
Opioid-Related Litigation Settlement liability, Current	0.0		0.0
Opioid-Related Litigation Settlement liability, Non-current	0.0		0.0
Liabilities Subject to Compromise	(6,402.7)		(6,402.7)
Shareholders' equity	$ 48.9		$ 48.9
Operating Lease, Weighted Average Discount Rate, Percent	8.85%		8.85%