Summary of Significant Accounting Policies - Revenue Recognition (Details)			3 Months Ended		9 Months Ended
	Sep. 03, 2020 kg	Apr. 15, 2020 USD ($) item	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)
Disaggregation of Product Revenue
Practical Expedients, not disclose the value of unsatisfied performance obligations					true
Net Income (Loss) Attributable to Parent			$ (7,866,000)	$ (7,555,000)	$ (25,040,000)	$ (32,580,000)
Product Donation Recorded As Revenue | Adoption Impact
Disaggregation of Product Revenue
Quantifying Misstatement, Adjustments In Revenue And Accounts Receivable			337,000
Net Income (Loss) Attributable to Parent			337,000
Manufacturing and Supply Agreement with Glenmark Life Sciences Limited [Member]
Disaggregation of Product Revenue
License agreement term (in years)	2 years 6 months
Agreement extension term	2 years
License termination term option	12 months
License termination activated upon written notice of material breach of Agreement	90 days
Manufacturing and Supply Agreement with Glenmark Life Sciences Limited [Member] | Minimum
Disaggregation of Product Revenue
Number of kilograms of crofelemer per year per agreement | kg	300
Atlas
Disaggregation of Product Revenue
Trial delay fee event of failure of initiation of phase 2 study					2,515,000
Total transaction price		$ 1,500,000			0
Total deferred transaction price					1,500,000
Excess loss amount			1,000,000		1,000,000
Allocated deferred transaction price					1,500,000
Deferred revenue recorded derecognized			1,500,000		1,500,000
Atlas | Patent purchase agreement
Disaggregation of Product Revenue
Upfront cash payments received		1,500,000
Atlas | License Agreement, Phase 2 Study [Member]
Disaggregation of Product Revenue
Upfront cash payments received		$ 1,500,000
Number of performance obligations | item		2
Total transaction price		$ 1,196,000
Atlas | License Agreement, Phase 2 Study [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-15
Disaggregation of Product Revenue
Performance obligations period		13 months 6 days
Atlas | License Agreement, Patent Sale [Member]
Disaggregation of Product Revenue
Upfront cash payments received					1,500,000
Total transaction price		$ 583,000
Revenue recognized			0		0
Mytesi
Disaggregation of Product Revenue
Product revenue			2,800,000	1,000,000	6,700,000	4,200,000
Neonorm
Disaggregation of Product Revenue
Product revenue			$ 13,000	$ 16,000	61,000	$ 83,000
License | Atlas | License Agreement
Disaggregation of Product Revenue
License term		10 years
Obligated initiate proof of concept		9 months
Trial delay fee event of failure of initiation of phase 2 study		$ 2,515,000			$ 2,500,000
License | Atlas | License Agreement | Minimum
Disaggregation of Product Revenue
Number of trial delay payments | item		3
License | Atlas | License Agreement | Maximum
Disaggregation of Product Revenue
Phase 2 completion period		5 years