Summary of Significant Accounting Policies - Collaboration Revenue (Details) - USD ($)		3 Months Ended	6 Months Ended	12 Months Ended
	Jan. 27, 2017	Jun. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Collaboration Revenue
Deferred collaboration revenue		$ 1,451,789	$ 1,451,789
Accounting Standards Update 2016-09
Collaboration Revenue
Unrecognized deferred tax assets				$ 0
Cumulative-effect adjustment				$ 0
Elanco
Collaboration Revenue
Initial upfront payment received	$ 2,548,689
Past product and development expenses reimbursement received	1,048,689
Receivable upon successful completion of a dose ranging study	1,000,000
Receivable upon the first commercial sale of license product for acute indications of diarrhea	2,000,000
Receivable upon the first commercial sale of license product for chronic indications of diarrhea	3,000,000
Upfront payment and expense reimbursement recognized as revenue			$ 2,548,689
Estimated development period for revenue recognition (in years)			1 year
Collaboration revenue recognized from unreimbursed expenses		197,876	$ 486,042
Collaboration revenue recognized from upfront payment and expense reimbursement		835,076	1,582,942
Deferred collaboration revenue		1,451,789	1,451,789
Unreimbursed expenses		$ 197,876	$ 197,876
Elanco | Net sales of licensed products exceeding $100.0 million
Collaboration Revenue
Additional payment receivable upon achievement	25,000,000
Aggregate minimum net sales of license products to be achieved	100,000,000
Elanco | Net sales of licensed products exceeding $250.0 million
Collaboration Revenue
Additional payment receivable upon achievement	30,000,000
Aggregate minimum net sales of license products to be achieved	250,000,000
Elanco | Maximum
Collaboration Revenue
Additional payment receivable upon achievement	$ 61,000,000