Agreements (Details) (USD $)	3 Months Ended								12 Months Ended			1 Months Ended	3 Months Ended	12 Months Ended			170 Months Ended		1 Months Ended	12 Months Ended	170 Months Ended				1 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2012	May 31, 2005 Roche Development and Commercialization License Exclusive license Kadcyla	Jun. 30, 2013 Roche Development and Commercialization License Exclusive license Kadcyla	Jun. 30, 2014 Roche Development and Commercialization License Exclusive license Kadcyla	Jun. 30, 2012 Roche Development and Commercialization License Exclusive license Kadcyla	May 31, 2000 Roche Development and Commercialization License Exclusive license Kadcyla Maximum	Jun. 30, 2014 Roche Development and Commercialization License Exclusive license Kadcyla Development milestones	May 31, 2000 Roche Development and Commercialization License Exclusive license Kadcyla Development milestones	Feb. 28, 2013 Roche Development and Commercialization License Exclusive license Kadcyla Regulatory milestones	Jun. 30, 2014 Roche Development and Commercialization License Exclusive license Kadcyla Regulatory milestones item	Jun. 30, 2014 Roche Development and Commercialization License Exclusive license Kadcyla Regulatory milestones	May 31, 2000 Roche Development and Commercialization License Exclusive license Kadcyla Regulatory milestones	Jun. 30, 2014 Roche Development and Commercialization License Exclusive license Kadcyla Regulatory milestones in Japan	Jun. 30, 2014 Roche Development and Commercialization License Exclusive license Kadcyla Regulatory milestones in Europe	May 31, 2000 Roche Right-to-test agreement Undisclosed Target item	May 31, 2000 Roche Right-to-test agreement Undisclosed Target Maximum	May 31, 2000 Roche Right-to-test agreement Undisclosed Target Development milestones	May 31, 2000 Roche Right-to-test agreement Undisclosed Target Regulatory milestones	Jun. 30, 2014 Roche Right-to-test agreement Undisclosed Target IND application filed	May 31, 2000 Roche Right-to-test agreement Undisclosed Target Sales milestones
Collaborative Agreements disclosures
Payments received under collaboration agreement												$ 2,000,000					$ 13,500,000		$ 10,500,000		$ 20,500,000
License exercise fee, per license																									1,000,000
Potential milestone payments receivable																44,000,000		13,500,000		5,000,000	5,000,000	30,500,000	5,000,000	5,000,000		38,000,000	8,000,000	20,000,000	1,000,000	10,000,000
Amount of arrangement consideration included in license and milestone fees	305,000	305,000	25,678,000	13,167,000	855,000	22,010,000	429,000	933,000	39,455,000	24,227,000	9,161,000
Number of milestone payments received																				2
Period in arrears to receive royalty reports and payments related to sales of Kadcyla														3 months
Royalties on net sales of Kadcyla	3,400,000	2,558,000	2,335,000	2,053,000	592,000				10,346,000	592,000			592,000	10,300,000	0
Number of undisclosed targets with exclusive licenses																									4
Payment received and deferred																									$ 5,000,000
Term of agreement																									8 years