Segment Data (Schedule of Net Sales from External Customers by Products) (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 27, 2025 USD ($)	Jun. 28, 2024 USD ($)	Jun. 27, 2025 USD ($) segement	Jun. 28, 2024 USD ($)
Segment Reporting Information
Net sales	$ 485.1	$ 514.3	$ 905.0	$ 982.1
Number of Reportable Segments | segement			2
Specialty Brands
Segment Reporting Information
Net sales	264.3	274.5	$ 471.6	531.8
Specialty Brands | Operating Segments
Segment Reporting Information
Net sales	264.3	274.5	471.6	531.8
Specialty Generics
Segment Reporting Information
Net sales	220.8	239.8	433.4	450.3
Specialty Generics | Operating Segments
Segment Reporting Information
Net sales	220.8	239.8	433.4	450.3
Acthar | Specialty Brands
Segment Reporting Information
Net sales	175.1	117.7	290.5	220.5
Inomax | Specialty Brands
Segment Reporting Information
Net sales	61.9	66.4	124.4	136.6
Therakos immunotherapy | Specialty Brands
Segment Reporting Information
Net sales	0.0	67.2	0.0	125.4
Amitiza [Member] | Specialty Brands
Segment Reporting Information
Net sales	17.2	15.3	37.4	34.7
Other | Specialty Brands
Segment Reporting Information
Net sales	2.1	2.6	3.9	3.3
Opioids | Specialty Generics
Segment Reporting Information
Net sales	73.2	95.2	156.9	177.1
ADHD | Specialty Generics
Segment Reporting Information
Net sales	48.7	41.8	95.9	73.5
Addiction Treatment | Specialty Generics
Segment Reporting Information
Net sales	26.5	21.0	45.0	36.4
Other Generics | Specialty Generics
Segment Reporting Information
Net sales	0.6	3.6	4.5	5.1
Generics | Specialty Generics
Segment Reporting Information
Net sales	149.0	161.6	302.3	292.1
Controlled substances | Specialty Generics
Segment Reporting Information
Net sales	27.5	26.4	46.6	49.3
APAP | Specialty Generics
Segment Reporting Information
Net sales	39.6	47.3	73.4	99.0
Other API | Specialty Generics
Segment Reporting Information
Net sales	4.7	4.5	11.1	9.9
API | Specialty Generics
Segment Reporting Information
Net sales	71.8	78.2	131.1	158.2
Terlivaz | Specialty Brands
Segment Reporting Information
Net sales	$ 8.0	$ 5.3	$ 15.4	$ 11.3