Fair Value Measurements - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net proceeds from sale of business	$ 187.8	$ 182.5	$ 5.2
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%
Rate of return (percent)		7.92%
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
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]
Net proceeds from sale of business		$ 250.0
Increase (decrease) in fair value of milestone payment	$ (95.3)	$ 22.1
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)	0.10
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
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