Collaborative Arrangements (Details) (USD $)	1 Months Ended	3 Months Ended	9 Months Ended	0 Months Ended	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		12 Months Ended
	Jul. 31, 2014 GlaxoSmithKline [Member]	Sep. 30, 2014 GlaxoSmithKline [Member]	Sep. 30, 2014 GlaxoSmithKline [Member]	Feb. 01, 2012 Merck [Member]	Sep. 30, 2014 Merck [Member]	Sep. 30, 2013 Merck [Member]	Sep. 30, 2014 Merck [Member]	Sep. 30, 2013 Merck [Member]	Sep. 30, 2014 Arch [Member]	Sep. 30, 2013 Arch [Member]	Sep. 30, 2014 Arch [Member]	Sep. 30, 2013 Arch [Member]	Dec. 31, 2013 Arch [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Proceeds from license fees received	$ 6,000,000
Contingent payment	19,000,000
Milestones receivable	11,500,000
Term of milestone agreement	3 years
Minimum milestone receivable	5,750,000.00
Maximum milestone receivable	38,500,000.0
License extension acceptance period	3 years
Revenue Recognition, Milestone Method, Termination Notice Period	90 days
Deferred Revenue		5,500,000	5,500,000		1,600,000		1,600,000
License and Services Revenue		500,000	500,000		500,000	500,000	1,500,000	1,300,000
Term of collaborative research and development agreement (years)				5 years
Sales Revenue, Goods, Net									200,000	0	300,000	2,100,000
Allowance for Doubtful Accounts Receivable, Charge-offs													$ 387,000