Segment Data (Schedule of Net Sales from External Customers by Products) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Apr. 01, 2022
Segment Reporting Information
Net sales	$ 424.6	$ 490.9
Specialty Brands | Operating Segments
Segment Reporting Information
Net sales	252.0	339.4
Specialty Generics
Segment Reporting Information
Net sales	172.6	151.5
Specialty Generics | Operating Segments
Segment Reporting Information
Net sales	172.6	151.5
Acthar | Specialty Brands
Segment Reporting Information
Net sales	82.0	127.7
Inomax | Specialty Brands
Segment Reporting Information
Net sales	82.7	99.0
Therakos immunotherapy | Specialty Brands
Segment Reporting Information
Net sales	58.7	59.9
Amitiza [Member] | Specialty Brands
Segment Reporting Information
Net sales	24.5	47.7
Other | Specialty Brands
Segment Reporting Information
Net sales	1.9	5.1
Opioids | Specialty Generics
Segment Reporting Information
Net sales	62.2	50.0
ADHD | Specialty Generics
Segment Reporting Information
Net sales	22.4	10.8
Addiction Treatment | Specialty Generics
Segment Reporting Information
Net sales	15.6	15.9
Other Generics | Specialty Generics
Segment Reporting Information
Net sales	1.8	2.8
Generics | Specialty Generics
Segment Reporting Information
Net sales	102.0	79.5
Controlled substances | Specialty Generics
Segment Reporting Information
Net sales	18.5	20.4
APAP | Specialty Generics
Segment Reporting Information
Net sales	46.4	46.3
Other API | Specialty Generics
Segment Reporting Information
Net sales	5.7	5.3
API | Specialty Generics
Segment Reporting Information
Net sales	70.6	72.0
Terlivaz | Specialty Brands
Segment Reporting Information
Net sales	$ 2.2	$ 0.0