Reorganizations (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended			6 Months Ended	9 Months Ended
	Jun. 16, 2022	Oct. 12, 2020	Sep. 30, 2022	Sep. 30, 2022	Sep. 24, 2021	Jun. 16, 2022	Sep. 24, 2021	Dec. 31, 2021
Reorganizations [Line Items]
Adequate Protection Payment, Expense					$ 15.8	$ 28.8	$ 46.1
Restructuring Support Agreement, Common Stock Share Percentage Reorganized New Company	100.00%					100.00%
Accrued interest			$ 71.1	$ 71.1				$ 17.0
Cash Paid, Reorganization items				9.9		$ 304.1	209.1
Restructuring Support Agreement, Proposed Settlement of General Unsecured Claims	$ 135.0					$ 135.0
Class of Warrant or Right, Outstanding	3,290,675					3,290,675
Opioid Warrants, Par value	$ 0.01					$ 0.01
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 Three and Four	32.5					32.5
Acthar Gel-Related Settlement, Payment Year Six and Seven	$ 62.5					$ 62.5
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 103.40					$ 103.40
Debt Instrument, Face Amount			3,583.6	3,583.6
Debtor Reorganization Items, Success Fees				0.0		$ 44.3	0.0
Debtor Reorganization Items, Net, Prepaid Expense Write-Off				0.0		9.2	0.0
Debtor Reorganization Items, Gain (Loss) on Settlement of Other Claims, Net				0.0		5.4	(0.5)
Reorganization items, net			$ (14.2)	$ (17.7)	(126.2)	(630.9)	(329.2)
Ordinary shares, shares issued (in shares)			0	0
Medicaid lawsuit liability	$ 260.0		$ 16.5	$ 16.5		260.0		0.0
Reorganization, Chapter 11, Plan Effect Adjustment
Reorganizations [Line Items]
Accrued interest	(13.0)					(13.0)
Contingent Consideration, Liability	(41.8)					(41.8)
Gain on settlement of liabilities subject to compromise	943.7			$ 0.0		$ (943.7)	0.0
Payment for Debt Extinguishment or Debt Prepayment Cost	$ (900.0)
Ordinary shares, shares issued (in shares)	13,170,932		13,170,932	13,170,932		13,170,932
Medicaid lawsuit liability	$ 16.5					$ 16.5
Reorganization, Chapter 11, Fresh-Start Adjustment
Reorganizations [Line Items]
Accrued interest	0.0					0.0
Reorganization Items, net, Loss on Fresh-Start Adjustments	(1,354.6)			$ 0.0		1,354.6	0.0
Medicaid lawsuit liability	0.0					0.0
Terlipressin Contingent Consideration
Reorganizations [Line Items]
Contingent Consideration, Liability	20.0					20.0
Terlipressin Contingent Consideration | Terlipressin [Member]
Reorganizations [Line Items]
Revenue from Customer, Cumulative Threshold	100.0					100.0
Maximum
Reorganizations [Line Items]
Loss Contingency, Estimate of Possible Loss			$ 48.2	48.2
Opioid Claimant Trust [Member]
Reorganizations [Line Items]
Restructuring Support Agreement Proposed Settlement, Year Three through Seven	150.0
Restructuring Support Agreement ProposedSettlement, Payment Year One and Two	200.0					200.0
Restructuring Support Agreement Proposed Settlement, Upfront Payment	450.0					450.0
Opioid-Related Settlement	1,725.0					1,725.0
Opioid-Related Settlement, Upfront Payment, Prefunded Amount	2.6					2.6
Restructuring Support Agreement Proposed Settlement, Year Eight	125.0
Opioid Claimant Trust [Member] | Reorganization, Chapter 11, Plan Effect Adjustment
Reorganizations [Line Items]
Opioid-Related Settlement	$ 1,725.0					$ 1,725.0
Opioid Claimant Trust [Member] | Other Ownership Interest [Member]
Reorganizations [Line Items]
Restructuring Support Agreement, Warrants Common Stock Share Percentage Reorganized New Company	19.99%					19.99%
Medicaid Lawsuit [Member] | Maximum
Reorganizations [Line Items]
Loss Contingency, Estimate of Possible Loss	$ 640.0					$ 640.0
Term Loan due 2024
Reorganizations [Line Items]
Secured Debt			0.0	0.0				1,396.5
Debt Instrument, Face Amount			0.0	0.0
Term Loan due 2025
Reorganizations [Line Items]
Secured Debt			0.0	0.0				370.7
Debt Instrument, Face Amount			0.0	0.0
5.75% Senior Notes
Reorganizations [Line Items]
Debt Instrument, Face Amount			0.0	0.0
5.625% Senior Notes
Reorganizations [Line Items]
Debt Instrument, Face Amount			0.0	0.0
5.50% Senior Notes
Reorganizations [Line Items]
Debt Instrument, Face Amount			0.0	0.0
10.00% Second Lien Senior Notes
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	10.00%					10.00%
Secured Debt			234.8	234.8				0.0
Debt Instrument, Face Amount	$ 322.9		321.9	321.9		$ 322.9
9.50% Debenture
Reorganizations [Line Items]
Debt Instrument, Face Amount			0.0	0.0
8.00% Debenture
Reorganizations [Line Items]
Debt Instrument, Face Amount			0.0	0.0
4.75% Senior Notes
Reorganizations [Line Items]
Debt Instrument, Face Amount			0.0	0.0
Unsecured Debt
Reorganizations [Line Items]
Increase (Decrease) in Interest Payable, Net					17.7	$ 46.5	64.2
Eleven Point Five Percent First Lien Senior Secured Notes
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	11.50%					11.50%
Secured Debt			650.0	650.0				0.0
Debt Instrument, Face Amount			650.0	650.0
Receivables Financing Facility
Reorganizations [Line Items]
Debt Instrument, Face Amount	$ 200.0					$ 200.0
10.00% First Lien Senior Notes
Reorganizations [Line Items]
Secured Debt			473.9	473.9				495.0
Debt Instrument, Face Amount	495.0		495.0	495.0		495.0
2017 Replacement Term Loan
Reorganizations [Line Items]
Secured Debt			1,222.8	1,222.8				0.0
Debt Instrument, Face Amount	1,392.9		1,382.8	1,382.8		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]
Secured Debt			327.2	327.2				0.0
Debt Instrument, Face Amount	369.7		367.1	367.1		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
Reorganizations [Line Items]
Secured Debt			0.0	0.0				900.0
Debt Instrument, Face Amount			0.0	0.0
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 Second Lien Notes (Existing Notes)
Reorganizations [Line Items]
Secured Debt			0.0	0.0				$ 322.9
Debt Instrument, Face Amount	322.9		$ 0.0	$ 0.0		322.9
Secured Debt
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Increase (Decrease)		200.00%
Adequate Protection Payment, Cash Paid					$ 16.4	28.8	$ 45.5
Restructuring Support Agreement, Proposed Long-Term Debt	$ 375.0					$ 375.0
Unsecured Debt | 5.625% Senior Notes
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.625%					5.625%
Senior Notes | 5.75% Senior Notes
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.75%					5.75%
Senior Notes | 5.50% Senior Notes
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.50%					5.50%
Senior Notes | 10.00% Second Lien Senior Notes
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	10.00%					10.00%
Senior Notes | 4.75% Senior Notes
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.75%					4.75%
Senior Notes | Eleven Point Five Percent First Lien Senior Secured Notes
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	11.50%					11.50%
Debentures | 9.50% Debenture
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	9.50%					9.50%
Debentures | 8.00% Debenture
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	8.00%					8.00%
Term Loans due Sept 2024 and Feb 2025
Reorganizations [Line Items]
Debt Instrument, Interest Rate, Increase (Decrease)		250.00%