Deferred Revenue (Details) - USD ($)		1 Months Ended	3 Months Ended		12 Months Ended
	Jan. 14, 2020	Oct. 31, 2014	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2016	Dec. 31, 2019
Deferred Revenue Arrangement [Line Items]
Deferred revenue			$ 11,630,000			$ 12,076,000
Baxter Healthcare Organization
Deferred Revenue Arrangement [Line Items]
Upfront payment		$ 20,000,000
Recognized deferred revenue			500,000	$ 500,000
Deferred revenue			$ 8,600,000			9,100,000
Refund eligible for, percent of upfront fee			25.00%
Partial refund			$ 6,600,000
Wanbang Biopharmaceutical
Deferred Revenue Arrangement [Line Items]
Upfront payment					$ 4,000,000
Recognized deferred revenue			100,000	$ 100,000
Deferred revenue			2,900,000			$ 3,000,000
Sun Pharma Agreements
Deferred Revenue Arrangement [Line Items]
Upfront payment	$ 100,000
Recognized deferred revenue			$ 2,500