Agreements (Details) (USD $)	3 Months Ended								12 Months Ended			1 Months Ended	3 Months Ended	12 Months Ended		12 Months Ended		1 Months Ended				1 Months Ended
	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2011	May 31, 2000 Roche Development, Manufacturing and Commercialization Kadcyla	Jun. 30, 2013 Roche Development, Manufacturing and Commercialization Kadcyla	Jun. 30, 2013 Roche Development, Manufacturing and Commercialization Kadcyla	May 31, 2000 Roche Development, Manufacturing and Commercialization Kadcyla Maximum	Jun. 30, 2013 Roche Development, Manufacturing and Commercialization Kadcyla Development milestones	May 31, 2000 Roche Development, Manufacturing and Commercialization Kadcyla Development milestones	Feb. 28, 2013 Roche Development, Manufacturing and Commercialization Kadcyla Regulatory milestones	May 31, 2000 Roche Development, Manufacturing and Commercialization Kadcyla Regulatory milestones	Jun. 30, 2013 Roche Development, Manufacturing and Commercialization Kadcyla Regulatory milestones in Japan	Jun. 30, 2013 Roche Development, Manufacturing and Commercialization 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	May 31, 2000 Roche Right-to-test agreement Undisclosed Target Sales milestones	Jun. 30, 2013 Roche Right-to-test agreement Undisclosed Target IND application filed
Collaborative Agreements disclosures
Payments received under collaboration agreement												$ 2,000,000				$ 13,500,000		$ 10,500,000
License exercise fee, per license																						1,000,000
Potential milestone payments receivable															44,000,000		13,500,000		30,500,000	5,000,000	5,000,000		38,000,000	8,000,000	20,000,000	10,000,000	1,000,000
Revenue recognized upon achievement of the milestone	855,000	22,010,000	429,000	933,000	950,000	999,000	6,025,000	1,187,000	24,227,000	9,161,000	6,393,000
Period in arrears to receive royalty reports and payments related to sales of Kadcyla														3 months
Royalties on net sales of Kadcyla	592,000								592,000				592,000
Number of undisclosed targets with exclusive licenses																						4
Payment received and deferred																						$ 5,000,000
Term of agreement																						8 years