Segment Data (Schedule of Net Sales from External Customers by Products) (Details) - USD ($) $ in Millions		3 Months Ended			6 Months Ended	9 Months Ended
		Sep. 29, 2023	Sep. 30, 2022	Sep. 30, 2022	Jun. 16, 2022	Sep. 29, 2023
Segment Reporting Information
Net sales		$ 497.0	$ 550.4	$ 465.4	$ 874.6	$ 1,396.6
Specialty Brands | Operating Segments
Segment Reporting Information
Net sales		286.2	361.7	303.5	587.1	818.3
Specialty Generics
Segment Reporting Information
Net sales		210.8	188.7	161.9	287.5	578.3
Specialty Generics | Operating Segments
Segment Reporting Information
Net sales		210.8	188.7	161.9	287.5	578.3
Acthar | Specialty Brands
Segment Reporting Information
Net sales		122.1	153.2	125.7	221.9	320.9
Inomax | Specialty Brands
Segment Reporting Information
Net sales		72.9	94.2	80.7	165.8	232.5
Therakos immunotherapy | Specialty Brands
Segment Reporting Information
Net sales		66.0	68.2	58.0	109.6	187.6
Amitiza [Member] | Specialty Brands
Segment Reporting Information
Net sales	[1]	18.3	42.9	37.1	81.5	61.4
Other | Specialty Brands
Segment Reporting Information
Net sales		2.5	3.2	2.0	8.3	5.9
Opioids | Specialty Generics
Segment Reporting Information
Net sales		65.9	55.2	46.5	88.8	200.2
ADHD | Specialty Generics
Segment Reporting Information
Net sales		41.5	13.4	11.6	17.5	82.9
Addiction Treatment | Specialty Generics
Segment Reporting Information
Net sales		15.1	19.1	16.6	30.0	46.8
Other Generics | Specialty Generics
Segment Reporting Information
Net sales		3.4	3.0	2.9	4.9	7.6
Generics | Specialty Generics
Segment Reporting Information
Net sales		125.9	90.7	77.6	141.2	337.5
Controlled substances | Specialty Generics
Segment Reporting Information
Net sales		22.0	21.4	19.7	37.6	61.4
APAP | Specialty Generics
Segment Reporting Information
Net sales		57.4	69.2	57.9	96.5	163.6
Other API | Specialty Generics
Segment Reporting Information
Net sales		5.5	7.4	6.7	12.2	15.8
API | Specialty Generics
Segment Reporting Information
Net sales		84.9	98.0	84.3	146.3	240.8
Terlivaz | Specialty Brands
Segment Reporting Information
Net sales		$ 4.4	$ 0.0	$ 0.0	$ 0.0	$ 10.0

[1] Amitiza consists of both product net sales and royalties. Refer to Note 3 for further details on Amitiza's revenues.