Liability Related to Sale of Future Royalties (Details) $ in Thousands	1 Months Ended	3 Months Ended								4 Months Ended	12 Months Ended
	Apr. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Sep. 30, 2013 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2013 USD ($)
Liability Related to Sale of Future Royalties
Royalties on net sales of Kadcyla		$ (23)	$ 5,099	$ 4,625	$ 4,166	$ 3,400	$ 2,558	$ 2,335	$ 2,053		$ 13,867	$ 10,346	$ 592
Percentage of royalty payments if applicable threshold is met	85.00%
Transaction costs for royalty agreements											5,865
Movement in Deferred Revenue [Roll Forward]
Proceeds from sale of future royalties											194,135
Immunity Royalty Holdings, L.P
Liability Related to Sale of Future Royalties
Percentage of royalty payments	100.00%
Royalties on net sales of Kadcyla	$ 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%
Transaction costs for royalty agreements	$ 5,900
Movement in Deferred Revenue [Roll Forward]
Proceeds from sale of future royalties										$ 200,000
Non cash Kadcyla royalty revenue										(5,484)
Non cash interest expense recognized										5,146
Liability related to sale of future royalties - ending balance		$ 199,662								$ 199,662	$ 199,662
Effective annual interest rate										10.3