Segment Data (Schedule of Net Sales from External Customers by Products) (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 28, 2024 USD ($) reportable_segment	Jun. 30, 2023 USD ($)	Jun. 28, 2024 USD ($) reportable_segment	Jun. 30, 2023 USD ($)
Segment Reporting Information
Net sales	$ 514.3	$ 475.0	$ 982.1	$ 899.6
Number of Reportable Segments | reportable_segment	2		2
Specialty Brands | Operating Segments
Segment Reporting Information
Net sales	$ 274.5	280.1	$ 531.8	532.1
Specialty Generics
Segment Reporting Information
Net sales	239.8	194.9	450.3	367.5
Specialty Generics | Operating Segments
Segment Reporting Information
Net sales	239.8	194.9	450.3	367.5
Acthar | Specialty Brands
Segment Reporting Information
Net sales	117.7	116.8	220.5	198.8
Inomax | Specialty Brands
Segment Reporting Information
Net sales	66.4	76.9	136.6	159.6
Therakos immunotherapy | Specialty Brands
Segment Reporting Information
Net sales	67.2	62.9	125.4	121.6
Amitiza [Member] | Specialty Brands
Segment Reporting Information
Net sales	15.3	18.6	34.7	43.1
Other | Specialty Brands
Segment Reporting Information
Net sales	2.6	1.5	3.3	3.4
Opioids | Specialty Generics
Segment Reporting Information
Net sales	95.2	72.1	177.1	134.3
ADHD | Specialty Generics
Segment Reporting Information
Net sales	41.8	19.0	73.5	41.4
Addiction Treatment | Specialty Generics
Segment Reporting Information
Net sales	21.0	16.1	36.4	31.7
Other Generics | Specialty Generics
Segment Reporting Information
Net sales	3.6	2.4	5.1	4.2
Generics | Specialty Generics
Segment Reporting Information
Net sales	161.6	109.6	292.1	211.6
Controlled substances | Specialty Generics
Segment Reporting Information
Net sales	26.4	20.9	49.3	39.4
APAP | Specialty Generics
Segment Reporting Information
Net sales	47.3	59.8	99.0	106.2
Other API | Specialty Generics
Segment Reporting Information
Net sales	4.5	4.6	9.9	10.3
API | Specialty Generics
Segment Reporting Information
Net sales	78.2	85.3	158.2	155.9
Terlivaz | Specialty Brands
Segment Reporting Information
Net sales	$ 5.3	$ 3.4	$ 11.3	$ 5.6