Collaborative Arrangements (Details) - USD ($)	1 Months Ended						3 Months Ended		5 Months Ended
	Dec. 31, 2016	Apr. 30, 2016	Sep. 30, 2015	Aug. 31, 2015	Jul. 31, 2014	Feb. 29, 2012	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2014
Technology Transfer, Collaboration and License Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Termination notice period				30 days
Supply Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred revenue	$ 700,000						$ 700,000
Milestone revenue	750,000
Merck [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Sales revenue							1,800,000	$ 1,600,000
Merck [Member] | Technology Transfer, Collaboration and License Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Proceeds from license fees received				$ 5,000,000
Termination notice period				90 days
License and services revenue							0	600,000
Upfront License fee, period for recognition				2 years
Potential royalty revenue							15,000,000
Duration of license agreement				3 years
Right of refusal period				5 years
Merck [Member] | Supply Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Termination notice period						24 months
License and services revenue							300,000	300,000
Deferred revenue	$ 1,300,000						2,500,000
Upfront License fee, period for recognition						5 years
Term of collaborative research and development agreement (years)						5 years
Optional extension period						5 years
GlaxoSmithKline [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Proceeds from license fees received					$ 6,000,000
Revenue recognized		$ 7,500,000	$ 6,500,000						$ 5,000,000
Minimum milestone receivable							5,750,000.00
Maximum milestone receivable							38,500,000.0
Termination notice period					90 days
Term of milestone agreement					3 years
License and services revenue							0	500,000
Collaborative Arrangement [Member] | Merck [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
License and services revenue							900,000	200,000
Therapeutic Development Program [Member] | Collaborative Arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recognized							$ 100,000	$ 1,400,000