Segment Data (Schedule of Segment Reporting Information by Business Segment) (Details) - USD ($) $ in Millions		3 Months Ended				9 Months Ended
		Sep. 25, 2020		Jun. 26, 2020	Sep. 27, 2019	Sep. 25, 2020		Sep. 27, 2019
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		$ 698.3			$ 743.7	$ 1,530.6		$ 2,357.6
Operating Income (Loss)		41.5			8.3	(690.3)		(6.2)
Depreciation and amortization		(210.6)			(210.4)	(599.8)		(649.8)
Employee Benefits and Share-based Compensation		(4.3)			(7.8)	(17.6)		(30.6)
Opioid-related litigation settlement (Note 11)		(25.8)			0.0	(34.1)		0.0
Non-restructuring impairment charges		0.0		$ (63.5)	0.0	(63.5)		(113.5)
Medicaid lawsuit charge						(640.2)
Sales [Member]
Medicaid lawsuit charge		(0.7)			0.0	(535.1)		0.0
Medicaid Lawsuit [Member]
Decrease in revenue		22.2				30.8
Specialty Brands
Restructuring and related charges, net		0.0			0.0	(0.1)		(0.4)
Specialty Generics
Restructuring and related charges, net		0.0			(6.7)	(0.1)		(9.3)
Operating Segments
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		699.0			743.7	2,065.7		2,357.6
Operating Income (Loss)		334.9			313.3	920.5		1,019.6
Operating Segments | Specialty Brands
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		539.6			580.4	1,553.0		1,812.4
Operating Income (Loss)		291.8			277.0	765.0		894.2
Operating Segments | Specialty Generics
Net sales (includes refined estimate of the retrospective one-time charge of $0.7 and $535.1 related to the Medicaid lawsuit for the three and nine months ended September 25, 2020, respectively)		159.4			163.3	512.7		545.2
Operating Income (Loss)		43.1			36.3	155.5		125.4
Corporate, Non-Segment
Corporate and unallocated expenses	[1]	(42.1)			(15.3)	(152.3)		(76.6)
Depreciation and amortization		(236.1)			(234.9)	(675.5)		(723.5)
Restructuring and related charges, net		(3.2)			(7.2)	(15.8)		(11.2)
Separation Costs	[2]	(33.0)			(19.8)	(75.0)		(50.4)
Opioid-related litigation settlement (Note 11)		25.8	[3]		0.0	34.1	[3]	0.0
R&D Upfront Payment		0.0	[4]		(20.0)	(5.0)	[4]	(20.0)
Medicaid lawsuit charge		$ 0.5			$ 0.0	$ 640.2		$ 0.0

[1] Includes administration expenses and certain compensation, legal, environmental and other costs not charged to the Company's reportable segments.

[2] These costs, which are included in SG&A expenses, primarily relate to professional fees, costs incurred in preparation for the Chapter 11 proceedings as the Company works to resolve opioid and other legal uncertainties, incremental costs incurred to build out the corporate infrastructure of the previously planned spin-off of the Company's Specialty Generics segment, as well as rebranding initiatives associated with the Specialty Brands ongoing transformation.

[3] Represents the change in the Settlement Warrants' fair value. Refer to Note 12 for further information regarding the valuations of the Settlement Warrants.

[4] Represents R&D expense incurred related to an upfront payment made to acquire product rights in Japan for terlipressin during the nine months ended September 25, 2020 and an upfront payment made to Silence in connection with the license and collaboration agreement entered into during the three and nine months ended September 27, 2019.