Bankruptcy (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	Oct. 12, 2020	Dec. 29, 2023	Dec. 30, 2022	Jun. 16, 2022	Nov. 14, 2023	Dec. 31, 2021	Aug. 24, 2023	Aug. 23, 2023	Jun. 16, 2023
Reorganizations [Line Items]
Restructuring Support Agreement, Proposed Long-Term Debt		$ 375.0				$ 375.0
Restructuring Support Agreement, Common Stock Share Percentage Reorganized New Company		100.00%				100.00%
Cash paid for interest, net				$ 9.0	$ 164.1	$ 111.5	$ 316.8	$ 243.2
Accrued interest				20.1	29.0
Interest Protection Payment, Expense						28.8		63.1
Interest Protection Payment, Paid						$ 28.8		66.7
Debt instrument, face amount				1,647.8	3,534.1
Class of Warrant or Right, Outstanding		3,290,675				3,290,675
Opioid-Related Settlement, Warrants Common Stock Share Percentage Reorganized New Company		19.99%				19.99%
Opioid Warrants, Par value		$ 0.01				$ 0.01
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 99.36	$ 103.40				$ 103.40	$ 99.36
Acthar Gel-Related Settlement, Term		7 years				7 years
Acthar Gel-Related Settlement, Upfront Payment		$ 15.0				$ 15.0
Acthar Gel-Related Settlement, Payment Year One		15.0				15.0
Acthar Gel-Related Settlement, Payment Year Two and Three		20.0				20.0
Acthar Gel-Related Settlement, Payment Year Six and Seven		62.5				62.5
Settlement of General Unsecured Claims		135.0				135.0
Payments for Repurchase of Warrants					4.0
Issuance of external debt		650.0		0.0	0.0	650.0	$ 380.0	0.0
Acthar Gel-Related Settlement, Payment Year Four and Five		32.5				32.5
Opioid-Related Litigation Settlement, Payment Year One											$ 200.0
Opioid-Related Litigation Settlement, Final Payment									$ 250.0
2023 Restructuring Support Agreement, Trust Contingent Value Rights, Share Percentage of Reorganized New Company										5.00%
2023 Restructuring Support Agreement, Equity Value of Reorganized Debtors										$ 3,776.0
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	1,036,649						1,036,649
Acthar Gel-Related Settlement, total obligation		260.0		236.1		260.0
Warrants and Rights Outstanding, Term	4 years						4 years
Opioid Claimant Trust [Member]
Reorganizations [Line Items]
Opioid-Related Settlement, Year Three through Seven		150.0				150.0
2023 Restructuring Support Agreement
Reorganizations [Line Items]
Restructuring Support Agreement, Proposed Long-Term Debt	$ 1,650.0						$ 1,650.0
Debt Instrument, Increase (Decrease), Net	2,861.8
StrataGraft PRV
Reorganizations [Line Items]
Other Indefinite-lived Intangible Assets		100.0				100.0
StrataGraft PRV | Mallinckrodt
Reorganizations [Line Items]
Proceeds from Sale of Intangible Assets					65.0
StrataGraft PRV | General Unsecured Claims Trust
Reorganizations [Line Items]
Proceeds from Sale of Intangible Assets					35.0
Terlipressin [Member]
Reorganizations [Line Items]
Contingent consideration		20.0				20.0
Revenue from Customer, Cumulative Threshold		100.0				100.0
Reorganization, Chapter 11, Plan Effect Adjustment
Reorganizations [Line Items]
Accrued interest	(31.5)	(13.0)				(13.0)	(31.5)
Acthar Gel-Related Settlement, Current	21.4	16.5				16.5	21.4
Payment for Debt Extinguishment or Debt Prepayment Cost		(900.0)
Contingent consideration		$ (41.8)				$ (41.8)
Ordinary shares, shares issued (in shares)		13,170,932				13,170,932
Reorganization, Chapter 11, Plan Effect Adjustment | StrataGraft PRV | General Unsecured Claims Trust
Reorganizations [Line Items]
Contingent consideration		$ 35.0				$ 35.0
Secured Debt
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Increase (Decrease)			200.00%
Term Loans due Sept 2024 and Feb 2025 [Member]
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Increase (Decrease)			250.00%
Five Point Six Two Five Percent Note | Senior Notes
Reorganizations [Line Items]
Stated interest rate		5.625%				5.625%
Five Point Five Percent Notes [Member] | Senior Notes
Reorganizations [Line Items]
Stated interest rate		5.50%				5.50%
Debentures
Reorganizations [Line Items]
Increase (Decrease) in Interest Payable, Net						$ 46.5		$ 93.0
2017 Replacement Term Loan
Reorganizations [Line Items]
Debt instrument, face amount		$ 1,392.9		0.0	1,374.1	1,392.9
2017 Replacement Term Loan | Reorganization, Chapter 11, Plan Effect Adjustment
Reorganizations [Line Items]
Debt instrument, face amount		1,392.9				1,392.9
2018 Replacement Term Loan
Reorganizations [Line Items]
Debt instrument, face amount		369.7		0.0	364.8	369.7
2018 Replacement Term Loan | Reorganization, Chapter 11, Plan Effect Adjustment
Reorganizations [Line Items]
Debt instrument, face amount		369.7				369.7
2017 Revolving Credit Facility | Reorganization, Chapter 11, Plan Effect Adjustment
Reorganizations [Line Items]
Payment for Debt Extinguishment or Debt Prepayment Cost		900.0
Ten Point Zero Percent First Lien Notes [Member]
Reorganizations [Line Items]
Debt instrument, face amount		495.0		0.0	495.0	495.0
Ten Point Zero Percent First Lien Notes [Member] | Reorganization, Chapter 11, Plan Effect Adjustment
Reorganizations [Line Items]
Debt instrument, face amount		495.0				495.0
Ten Point Zero Percent Second Lien Notes (Existing Notes)
Reorganizations [Line Items]
Debt instrument, face amount		322.9				322.9
Ten Point Zero Percent Second Lien Notes (Existing Notes) | Reorganization, Chapter 11, Plan Effect Adjustment
Reorganizations [Line Items]
Debt instrument, face amount		$ 322.9				$ 322.9
Ten Point Zero Percent Second Lien Notes (New 2L Notes)
Reorganizations [Line Items]
Debt instrument, face amount				0.0	321.9
Increase (Decrease) in Interest Payable, Net							48.5
Ten Point Zero Percent Second Lien Notes (New 2L Notes) | Senior Notes
Reorganizations [Line Items]
Stated interest rate		10.00%				10.00%
Eleven Point Five Percent First Lien Senior Secured Notes
Reorganizations [Line Items]
Debt instrument, face amount				0.0	650.0
Eleven Point Five Percent First Lien Senior Secured Notes | Reorganization, Chapter 11, Plan Effect Adjustment
Reorganizations [Line Items]
Issuance of external debt		$ 650.0
Receivables Financing Facility
Reorganizations [Line Items]
Debt instrument, face amount		$ 200.0		0.0	0.0	$ 200.0
Takeback Term Loans
Reorganizations [Line Items]
Debt instrument, face amount	871.4						871.4
First-Out Takeback Term Loan Due November 2028
Reorganizations [Line Items]
Debt instrument, face amount	229.4			228.8	0.0		229.4
Second-Out Takeback Term Loan Due November 2028
Reorganizations [Line Items]
Debt instrument, face amount	$ 642.0			640.4	0.0		$ 642.0
Fourteen Point Seven Five Percent Second-Out Takeback Notes
Reorganizations [Line Items]
Stated interest rate	14.75%						14.75%
Debt instrument, face amount	$ 778.6			778.6	$ 0.0		$ 778.6
Five Point Seven Five Percent Notes | Senior Notes
Reorganizations [Line Items]
Stated interest rate		5.75%				5.75%
Four Point Seven Five Percent Note | Senior Notes
Reorganizations [Line Items]
Stated interest rate		4.75%				4.75%
Maximum
Reorganizations [Line Items]
Remedial cost, estimate				$ 47.9
First Lien Claimholders | 2023 Restructuring Support Agreement
Reorganizations [Line Items]
Restructuring Support Agreement, Equity Share Ownership of Reorganized New Company	92.30%
Second Lien Claimholders | 2023 Restructuring Support Agreement
Reorganizations [Line Items]
Restructuring Support Agreement, Equity Share Ownership of Reorganized New Company	7.70%
Opioid Claimant Trust [Member]
Reorganizations [Line Items]
Opioid-related Settlement		$ 1,725.0				$ 1,725.0
Opioid-Related Settlement, Upfront Payment		450.0				450.0
Opioid-Related Settlement, Payment Year One and Two		200.0				200.0
Opioid-Related Settlement, Year Eight		125.0				125.0
Opioid-Related Settlement, Upfront Payment, Prefunded Amount		2.6				2.6
Opioid Claimant Trust [Member] | Reorganization, Chapter 11, Plan Effect Adjustment
Reorganizations [Line Items]
Opioid-related Settlement		1,725.0				1,725.0
Medicaid Lawsuit [Member] | Maximum
Reorganizations [Line Items]
Remedial cost, estimate		$ 640.0				$ 640.0