Segment Data - Schedule of Net Sales from External Customers by Products (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 26, 2025	Sep. 27, 2024	Sep. 26, 2025	Sep. 27, 2024
Segment Reporting Information
Net sales	$ 753.1	$ 505.5	$ 1,658.1	$ 1,487.6
Operating Segments
Segment Reporting Information
Net sales	753.1	505.5	1,658.1
Specialty Brands
Segment Reporting Information
Net sales				817.8
Specialty Brands | Endo
Segment Reporting Information
Net sales	17.1		17.1
Specialty Brands | Operating Segments
Segment Reporting Information
Net sales	416.0	286.0	887.6	817.8
Generics
Segment Reporting Information
Net sales				669.8
Generics | Endo
Segment Reporting Information
Net sales	47.0		47.0
Generics | Operating Segments
Segment Reporting Information
Net sales	289.9	219.5	723.3	669.8
Sterile Injectables
Segment Reporting Information
Net sales				0.0
Sterile Injectables | Operating Segments
Segment Reporting Information
Net sales	47.2	0.0	47.2	0.0
Acthar Gel | Specialty Brands
Segment Reporting Information
Net sales	181.4	126.4	471.9	346.9
Xiaflex | Specialty Brands
Segment Reporting Information
Net sales	90.1	0.0	90.1	0.0
INOmax | Specialty Brands
Segment Reporting Information
Net sales	58.9	64.0	183.3	200.6
Amitiza | Specialty Brands
Segment Reporting Information
Net sales	18.8	18.8	56.2	53.5
Supprelin LA | Specialty Brands
Segment Reporting Information
Net sales	13.6	0.0	13.6	0.0
Percocet | Specialty Brands
Segment Reporting Information
Net sales	10.6	0.0	10.6	0.0
Testopel | Specialty Brands
Segment Reporting Information
Net sales	8.6	0.0	8.6	0.0
Terlivaz | Specialty Brands
Segment Reporting Information
Net sales	8.5	7.3	23.9	18.6
Edex | Specialty Brands
Segment Reporting Information
Net sales	6.6	0.0	6.6	0.0
Other | Specialty Brands
Segment Reporting Information
Net sales	18.9	1.9	22.8	5.2
Therakos | Specialty Brands
Segment Reporting Information
Net sales	0.0	67.6	0.0	193.0
Opioids | Generics
Segment Reporting Information
Net sales	70.4	85.9	227.3	263.0
ADHD | Generics
Segment Reporting Information
Net sales	48.9	41.3	144.8	114.8
Addiction treatment | Generics
Segment Reporting Information
Net sales	22.5	18.1	67.5	54.5
Lidoderm AG | Generics
Segment Reporting Information
Net sales	33.7	0.0	33.7	0.0
Other Generics | Generics
Segment Reporting Information
Net sales	47.3	0.9	51.8	6.0
Finished Dosage Generics | Generics
Segment Reporting Information
Net sales	222.8	146.2	525.1	438.3
APAP | Generics
Segment Reporting Information
Net sales	44.6	40.0	118.0	139.0
Controlled substances | Generics
Segment Reporting Information
Net sales	18.9	27.2	65.5	76.5
Other | Generics
Segment Reporting Information
Net sales	3.6	6.1	14.7	16.0
API | Generics
Segment Reporting Information
Net sales	67.1	73.3	198.2	231.5
Aplisol | Sterile Injectables
Segment Reporting Information
Net sales	11.6	0.0	11.6	0.0
Adrenalin | Sterile Injectables
Segment Reporting Information
Net sales	11.5	0.0	11.5	0.0
Vasostrict | Sterile Injectables
Segment Reporting Information
Net sales	4.8	0.0	4.8	0.0
Other sterile injectables | Sterile Injectables
Segment Reporting Information
Net sales	$ 19.3	$ 0.0	$ 19.3	$ 0.0