Segment Data (Schedule of Net Sales from External Customers by Products) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 29, 2024	Mar. 31, 2023
Segment Reporting Information
Net sales	$ 467.8	$ 424.6
Specialty Brands | Operating Segments
Segment Reporting Information
Net sales	257.3	252.0
Specialty Generics
Segment Reporting Information
Net sales	210.5	172.6
Specialty Generics | Operating Segments
Segment Reporting Information
Net sales	210.5	172.6
Acthar | Specialty Brands
Segment Reporting Information
Net sales	102.8	82.0
Inomax | Specialty Brands
Segment Reporting Information
Net sales	70.2	82.7
Therakos immunotherapy | Specialty Brands
Segment Reporting Information
Net sales	58.2	58.7
Amitiza [Member] | Specialty Brands
Segment Reporting Information
Net sales	19.4	24.5
Other | Specialty Brands
Segment Reporting Information
Net sales	0.7	1.9
Opioids | Specialty Generics
Segment Reporting Information
Net sales	81.9	62.2
ADHD | Specialty Generics
Segment Reporting Information
Net sales	31.7	22.4
Addiction Treatment | Specialty Generics
Segment Reporting Information
Net sales	15.4	15.6
Other Generics | Specialty Generics
Segment Reporting Information
Net sales	1.5	1.8
Generics | Specialty Generics
Segment Reporting Information
Net sales	130.5	102.0
Controlled substances | Specialty Generics
Segment Reporting Information
Net sales	22.9	18.5
APAP | Specialty Generics
Segment Reporting Information
Net sales	51.7	46.4
Other API | Specialty Generics
Segment Reporting Information
Net sales	5.4	5.7
API | Specialty Generics
Segment Reporting Information
Net sales	80.0	70.6
Terlivaz | Specialty Brands
Segment Reporting Information
Net sales	$ 6.0	$ 2.2