Summary of Significant Accounting Policies - Revenue Recognition - Collaboration Revenue (Details) - USD ($)				3 Months Ended		9 Months Ended
	Sep. 24, 2018	Nov. 01, 2017	Jan. 27, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Collaboration Revenue
Written notice period (in days)		90 days
Elanco
Collaboration Revenue
Non-refundable upfront payment received			$ 2,548,689
Product and development expense			$ 1,048,689
Estimated development period for revenue recognition (in years)						1 year
Collaboration revenue				$ 0	$ 637,200	$ 0	$ 1,734,100
Knight
Collaboration Revenue
License agreement term (in years)	15 years
Transfer price receivable upon achievement of certain regulatory and sales milestones	$ 18,000,000