Collaboration and License Agreements - Teva Narrative (Details) - USD ($)	3 Months Ended										12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Revenues	$ 2,169,500,000	$ 2,048,400,000	$ 1,933,700,000	$ 1,711,800,000	$ 1,927,800,000	$ 1,663,500,000	$ 1,608,000,000.0	$ 1,511,500,000			$ 7,863,400,000	$ 6,710,800,000	$ 5,872,200,000
Teva
Disaggregation of Revenue [Line Items]
Up-front payment received														$ 250,000,000.0
Revenue recognition, milestone method, revenue recognized									$ 35,000,000.0	$ 25,000,000.0
Development milestone achieved												60,000,000.0
Aggregate future development milestone payments the Company is eligible to receive											340,000,000.0
Collaborative arrangement, additional eligible aggregate payments											1,890,000,000.0
Revenues											206,500,000	$ 244,600,000	$ 221,500,000
Remaining performance obligation	$ 267,100,000										$ 267,100,000