Summary of Significant Accounting Policies - Revenue Recognition, PPE, Licensing and Research (Details)		1 Months Ended	12 Months Ended		24 Months Ended
	Dec. 31, 2016 USD ($)	Oct. 31, 2014 USD ($)	Dec. 31, 2018 USD ($) agreement shares	Dec. 31, 2017 USD ($) shares	Dec. 31, 2018 USD ($)
Revenue Recognition
Number of distribution and license agreements | agreement			2
Customers average payment term			30 days
Distributors average payment term			45 days
Contract liabilities			$ 14,329,000	$ 16,723,000	$ 14,329,000
Impairment losses			0	0
Bad-debt expense			0	0
Contract assets			0	0	0
Revenue performance obligation			$ 14,300,000	16,700,000	14,300,000
Remaining performance obligation practical expedient			true
Impairment of Long-lived Assets
Impairments of long-lived assets					0
Research and Product Development
Product development and research costs			$ 5,642,317	6,321,400
Investments Available for Sale
Fair value of investments			$ 10,818,059	24,648,459	10,818,059
Licensing Fees
Useful life			17 years
Research and Development
Research and Development Expense			$ 5,642,317	$ 6,321,400
Loss Per Share
Securities excluded from diluted loss per share calculation | shares			9,853,322	7,386,001
Statutory rate (as a percent)			21.00%	35.00%
License Agreement Terms [Member]
Research and Product Development
Product development and research costs			$ 1,100,000
Research and Development
Research and Development Expense			$ 1,100,000
Baxter Healthcare Organization
Licensing Fees
Useful life		10 years
Minimum
Property and Equipment
Useful life			3 years
Stock-Based Compensation
Market and performance-based stock unit awards service period			1 year
Maximum
Property and Equipment
Useful life			10 years
Stock-Based Compensation
Market and performance-based stock unit awards service period			2 years
Wanbang Biopharmaceutical
Revenue Recognition
Deferred Revenue			$ 3,200,000	$ 3,500,000	3,200,000
Upfront payment	$ 4,000,000
Deferred drug license revenue			$ 300,000	300,000
Baxter Healthcare Organization
Revenue Recognition
Upfront payment benefit percent			25.00%
Partial Refund			$ 6,600,000
Upfront payment		$ 20,000,000
Deferred drug license revenue			2,100,000	2,100,000
Contract liabilities			11,100,000	$ 13,200,000	11,100,000
Revenue performance obligation			11,100,000		11,100,000
Concentrate Products [Member]
Revenue Recognition
Reserve for returns			$ 0		$ 0