Liability Related to Sale of Future Royalties (Details) - Kadcyla - USD ($) $ in Thousands	1 Months Ended	9 Months Ended
	Apr. 30, 2015	Sep. 30, 2018
Contract with Customer, Liability [Line Items]
Percentage of royalty payments if applicable threshold is met	85.00%
IRH
Contract with Customer, Liability [Line Items]
Percentage of royalty payments	100.00%
Percentage of royalty payments if applicable threshold is met	15.00%
Proceeds from sale of future royalties - net	$ 200,000
Transaction costs for royalty agreements	5,900
Change in liability related to sale of future royalties
Liability related to sale of future royalties, net ? beginning balance		$ 169,413
Royalty payments received and paid		(23,658)
Non-cash interest expense recognized		8,192
Liability related to sale of future royalties, net ? ending balance		$ 153,947
Effective annual interest rate		7.30%
Prospective annual rate		5.8
IRH | Maximum
Contract with Customer, Liability [Line Items]
Royalties threshold	260,000
IRH | Minimum
Contract with Customer, Liability [Line Items]
Royalties threshold	$ 235,000