Revenue Recognition - Schedule of Revenue by Geographic Location (Details) - USD ($) $ in Millions		3 Months Ended															12 Months Ended
		Dec. 31, 2020	[1]	Sep. 30, 2020	[2]	Jun. 30, 2020	[3]	Mar. 31, 2020	Dec. 31, 2019	[4]	Sep. 28, 2019	[5]	Jun. 29, 2019	[6]	Mar. 30, 2019	[7]	Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Net sales		$ 1,289.5		$ 1,213.7		$ 1,219.1		$ 1,341.0	$ 1,322.8		$ 1,191.1		$ 1,149.0		$ 1,174.5		$ 5,063.3	[8]	$ 4,837.4	[8]	$ 4,731.7	[8]
United States
Disaggregation of Revenue [Line Items]
Net sales	[8]																3,441.1		3,225.6		3,098.3
Europe
Disaggregation of Revenue [Line Items]
Net sales	[8],[9]																1,350.6		1,335.8		1,347.6
All other countries
Disaggregation of Revenue [Line Items]
Net sales	[8],[10]																271.6		276.0		285.8
Ireland
Disaggregation of Revenue [Line Items]
Net sales																	$ 29.8		$ 23.4		$ 25.7

[1] Includes change in financial assets of $122.3 million and impairment charges of $144.4 million.

[2] Includes impairment charges of $202.4 million, change in financial assets of $22.2 million and loss on early debt extinguishment of $20.0 million.

[3] Includes Rosemont Pharmaceuticals business pre-tax loss of $21.1 million.

[4] Includes impairment charges of $141.6 million.

[5] Includes animal health divestiture pre-tax gain of $71.7 million, Ranitidine market withdrawal charges of $18.4 million, acquisition-related charges and contingent consideration adjustments of $18.1 million, and impairment charges of $10.9 million.

[6] Includes impairment charges of $27.8 million and restructuring charges and other termination benefits of $12.2 million.

[7] Includes change in financial assets of $10.4 million.

[8] The net sales by geography is derived from the location of the entity that sells to a third party.

[9] Includes Ireland net sales of $29.8 million, $23.4 million, and $25.7 million for the years ended December 31, 2020, December 31, 2019, and December 31, 2018, respectively.

[10] Includes revenue generated primarily in Israel, Mexico, Australia, and Canada.