Fair Value Measurements - Additional Information (Details) - USD ($) $ in Millions			3 Months Ended															12 Months Ended
	Jul. 08, 2019	Jan. 03, 2017	Dec. 31, 2019		Sep. 28, 2019		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, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net proceeds from sale of business																			$ 182.5	$ 5.2	$ 154.6
Gain (loss) on disposition of business					$ 71.7														71.7	0.0	0.0
Income recognized for change in asset			$ 3.6	[1]	$ 2.6	[2]	$ 5.5		$ 10.4		$ 122.8	$ 74.9		$ 0.6		$ (9.6)			22.1	188.7	(24.9)
Payment of guaranty liability																			1.8
Gain (loss) on settlement of contingent consideration																					17.4
Provision for new credit guarantees																					12.5
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Guarantee on certain obligations			$ 12.0																12.0		13.8
Provision for new credit guarantees																			$ 0.0	$ 0.0	12.5
CSCA
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net proceeds from sale of business	$ 182.5
Gain (loss) on disposition of business	$ 71.7
RX
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net proceeds from sale of business		$ 15.0
Royalty Pharma
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Sale price of divestiture - cash plus non-cash																					2,850.0
Net proceeds from sale of business																					2,200.0
Contingent proceeds from divestiture of business, milestone one, maximum																					250.0
Contingent proceeds from divestiture of business, milestone two, maximum																					$ 400.0
Volatility (percent)																			30.00%	30.00%
Rate of return (percent)																			7.92%	8.05%
Royalty Pharma Contingent Milestone Payments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net sales included in calculation for milestone payment																				$ 337.5
Royalty Pharma Contingent Milestone Payments | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Increase (decrease) in fair value of milestone payment																			$ 22.1	188.7
Royalty Pharma 2018 Contingent Milestone Payments | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Increase (decrease) in fair value of milestone payment																				(170.1)
Royalty Pharma 2020 Contingent Milestone Payments | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Increase (decrease) in fair value of milestone payment																				$ (18.6)
Long-term growth rate | CSCA
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discounted cash flow (percent)																				0.025
Indefinite-lived intangible assets, measurement input (percent)																				(0.003)
Long-term growth rate | RX
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Indefinite-lived intangible assets, measurement input (percent)																			0.000
Discount rate | CSCA
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discounted cash flow (percent)																				0.098
Indefinite-lived intangible assets, measurement input (percent)																				0.098
Discount rate | RX
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discounted cash flow (percent)																			0.102
Tax rate | CSCA
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discounted cash flow (percent)																				0.228
Indefinite-lived intangible assets, measurement input (percent)																				0.228
Change in Financial Assets | Royalty Pharma
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) on disposition of business																				$ 17.1
Forecast
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Royalty Pharma contingent payment sales threshold																		$ 400.0
Forecast | Royalty Pharma Contingent Milestone Payments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Royalty Pharma contingent payment sales threshold																		400.0
Net sales threshold to trigger milestone payment																		351.0
Write-off of contingent milestone payment if sales threshold is not met																		95.3
Income recognized for change in asset																		$ 304.7
Minimum | Tax rate | RX
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discounted cash flow (percent)																			0.191
Maximum | Tax rate | RX
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discounted cash flow (percent)																			0.217
Lumara product assets | Discount rate | CSCA
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Definite-lived intangible assets, measurement input																					13.50%
Lumara product assets | Five-year growth rate | CSCA
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Definite-lived intangible assets, measurement input																					(4.10%)

[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.