Earnings Per Share And Shareholder's Equity - Earnings Per Share (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended															12 Months Ended
	Dec. 31, 2019	[1]	Sep. 28, 2019	[2]	Jun. 29, 2019	[3]	Mar. 30, 2019	[3]	Dec. 31, 2018	Sep. 29, 2018	[4]	Jun. 30, 2018	[5]	Mar. 31, 2018	[6]	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Numerator:
Net income	$ (19.0)		$ 92.2		$ 9.0		$ 63.9		$ 81.5	$ (67.5)		$ 36.2		$ 80.8		$ 146.1	$ 131.0	$ 119.6
Denominator:
Basic (in shares)	136.1		136.0		136.0		135.9		135.9	137.4		138.1		140.8		136.0	137.8	142.3
Dilutive effect of share-based awards (in shares)																0.5	0.5	0.3
Diluted (in shares)	137.0		136.8		136.5		136.2		136.3	137.4		138.7		141.4		136.5	138.3	142.6
Antidilutive share-based awards outstanding (in shares)																1.5	1.4	0.8

[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.