Liability Related to Sale of Future Royalties (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended										6 Months Ended		12 Months Ended			21 Months Ended
	Apr. 30, 2015	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2016	Dec. 31, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2016
Liability Related to Sale of Future Royalties
Royalty revenue						$ 195			$ 5,099	$ 4,625	$ 4,166		$ 195	$ 195	$ 13,867	$ 10,346
Transaction costs for royalty agreements															5,865
Roll forward
Proceeds from sale of future royalties - net															194,135
Non-cash Kadcyla royalty revenue		$ (6,710)	$ (6,184)	$ (5,944)	$ (7,380)	(6,291)	$ (5,684)	$ (5,484)				$ (12,894)	(11,975)	(25,299)	(5,484)
Non-cash interest expense on liability related to sale of future royalties and convertible senior notes		3,647	5,018	4,956	$ 4,972	$ 5,059	$ 5,143	$ 5,437				8,665	$ 10,202	20,130	$ 5,437
Kadcyla
Liability Related to Sale of Future Royalties
Percentage of royalty payments if applicable threshold is met	85.00%
Kadcyla | IRH
Liability Related to Sale of Future Royalties
Percentage of royalty payments	100.00%
Royalty revenue	$ 235,000
Royalties on net sales of Kadcyla when royalties to the purchaser reach a specified milestone	$ 260,000
Percentage of royalty payments if applicable threshold is met	15.00%
Gross proceeds from sale of future royalties	$ 200,000
Transaction costs for royalty agreements	$ 5,900
Roll forward
Liability related to sale of future royalties, net — beginning balance			$ 188,899									188,899
Proceeds from sale of future royalties - net																	$ 194,135
Non-cash Kadcyla royalty revenue												(12,894)					(43,677)
Non-cash interest expense on liability related to sale of future royalties and convertible senior notes												8,323					33,870
Liability related to sale of future royalties, net — ending balance		$ 184,328		$ 188,899								$ 184,328		$ 188,899			$ 184,328
Effective annual interest rate																	7.70%