Fair Value Measurements - Additional Information (Details) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 28, 2019 USD ($)	Sep. 29, 2018 USD ($)	Sep. 28, 2019 USD ($)	Sep. 29, 2018 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2018 USD ($)	Jun. 29, 2019 USD ($)	Jun. 30, 2018 USD ($)	Dec. 31, 2017 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers among level 1, 2, and 3	$ 0.0			$ 0.0
Income recognized from change is asset	2.6	$ 74.9	$ 18.5	65.9
Measured on a recurring basis | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Potential contingent milestone payments	91.7		91.7			$ 323.2
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 | Measured on a recurring basis | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Increase (decrease) in fair value of milestone payment	2.6	74.9	18.5	65.9
Estimated fair valued contingent milestone payment	$ 91.7	200.4	91.7	$ 200.4		$ 323.2	$ 89.1	$ 125.5	$ 134.5
Royalty Pharma 2018 Contingent Milestone Payments | Measured on a recurring basis | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Increase (decrease) in fair value of milestone payment		67.7	53.2
Royalty Pharma 2020 Contingent Milestone Payments | Measured on a recurring basis | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Increase (decrease) in fair value of milestone payment		$ 7.2	$ 12.7
Royalty Pharma
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Volatility	30.00%	30.00%
Rate of return	7.99%	8.07%
Measurement Input, Long-term Revenue Growth Rate | CSCA
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Reporting Unit, Discounted Cash Flow, Measurement Input						0.025
Indefinite-lived Intangible Assets (Excluding Goodwill), Measurement Input						(0.003)
Measurement Input, Discount Rate | CSCA
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Reporting Unit, Discounted Cash Flow, Measurement Input						0.098
Indefinite-lived Intangible Assets (Excluding Goodwill), Measurement Input						0.098
Measurement Input, Tax Rate | CSCA
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Reporting Unit, Discounted Cash Flow, Measurement Input						0.228
Indefinite-lived Intangible Assets (Excluding Goodwill), Measurement Input						0.228
Scenario, Forecast
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Royalty Pharma contingent payment sales threshold					$ 400.0
Scenario, Forecast | Royalty Pharma Contingent Milestone Payments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net sales threshold to trigger milestone payment					351.0
Write-off of contingent milestone payment if sales threshold is not met					91.7
Royalty Pharma contingent payment sales threshold					400.0
Income recognized from change is asset					$ 308.3