Quarterly Financial Data (unaudited) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended																12 Months Ended
	Dec. 31, 2019		Sep. 28, 2019		Jun. 29, 2019		Mar. 30, 2019		Dec. 31, 2018		Sep. 29, 2018		Jun. 30, 2018		Mar. 31, 2018	[6]	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Condensed Financial Statements, Captions [Line Items]
Net sales	$ 1,322.8	[1]	$ 1,191.1	[2]	$ 1,149.0	[3]	$ 1,174.5	[3]	$ 1,195.2		$ 1,133.1	[4]	$ 1,186.4	[5]	$ 1,217.0		$ 4,837.4	[7]	$ 4,731.7	[7]	$ 4,946.2	[7]
Gross profit	480.9	[1]	412.8	[2]	430.8	[3]	448.8	[3]	443.0		424.8	[4]	471.0	[5]	492.7		1,773.3		1,831.5		1,979.5
Change in financial assets	(3.6)	[1]	(2.6)	[2]	(5.5)	[3]	(10.4)	[3]	(122.8)		(74.9)	[4]	(0.6)	[5]	9.6		(22.1)		(188.7)		24.9
Net income (loss)	$ (19.0)	[1]	$ 92.2	[2]	$ 9.0	[3]	$ 63.9	[3]	$ 81.5		$ (67.5)	[4]	$ 36.2	[5]	$ 80.8		$ 146.1		$ 131.0		$ 119.6
Earnings (loss) per share
Basic (in dollars per share)	$ (0.14)	[1],[8]	$ 0.68	[2],[8]	$ 0.07	[3],[8]	$ 0.47	[3],[8]	$ 0.60	[4]	$ (0.49)	[4],[6]	$ 0.26	[4],[5]	$ 0.57	[4]	$ 1.07		$ 0.95		$ 0.84
Diluted (in dollars per share)	$ (0.14)	[1],[8]	$ 0.67	[2],[8]	$ 0.07	[3],[8]	$ 0.47	[3],[8]	$ 0.60	[4]	$ (0.49)	[4],[6]	$ 0.26	[4],[5]	$ 0.57	[4]	$ 1.07		$ 0.95		$ 0.84
Weighted-average shares outstanding:
Basic (in shares)	136.1	[1]	136.0	[2]	136.0	[3]	135.9	[3]	135.9		137.4	[4]	138.1	[5]	140.8		136.0		137.8		142.3
Diluted (in shares)	137.0	[1]	136.8	[2]	136.5	[3]	136.2	[3]	136.3		137.4	[4]	138.7	[5]	141.4		136.5		138.3		142.6
Selected Quarterly Financial Information [Abstract]
Change in financial assets							$ 10.4
Impairment charges	$ 141.6		$ 10.9		$ 27.8						$ 221.8						$ 184.5		$ 224.4		$ 47.5
Restructuring					$ 12.2						$ 18.0						26.3		21.0		61.0
Gain on sale of business			71.7														$ 71.7		$ 0.0		$ 0.0
Impairment of intangible assets, indefinite-lived			18.1										$ 53.2
Ranitidine
Selected Quarterly Financial Information [Abstract]
Production Related Impairments or Charges			$ 18.4

[1] Includes impairment charges of $141.6 million.   First
Quarter   Second
Quarter ⁽²⁾   Third
Quarter ⁽³⁾   Fourth
Quarter Year Ended December 31, 2018               Net sales $ 1,217.0
  $ 1,186.4
  $ 1,133.1
  $ 1,195.2
Gross profit $ 492.7
  $ 471.0
  $ 424.8
  $ 443.0
Change in financial assets $ 9.6
  $ (0.6 )   $ (74.9 )   $ (122.8 ) Net income (loss) $ 80.8
  $ 36.2
  $ (67.5 )   $ 81.5
Earnings (loss) per share⁽¹⁾:               Basic $ 0.57
  $ 0.26
  $ (0.49 )   $ 0.60
Diluted $ 0.57
  $ 0.26
  $ (0.49 )   $ 0.60
Weighted average shares outstanding:               Basic 140.8
  138.1
  137.4
  135.9
Diluted 141.4
  138.7
  137.4
  136.3

[2] ludes impairment charges of $27.8 million and restructuring charges and other termination benefits of $12.2 million.(4) 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.

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

[4] Includes impairment charges of $221.8 million and restructuring charges and other termination benefits of $18.0 million.

[5] Includes acquisition-related charges and contingent consideration adjustments of $53.2 million.

[6] The sum of individual per share amounts may not equal due to rounding.

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

[8] The sum of individual per share amounts may not equal due to rounding.