License Agreements of Development and Commercialization Rights (Details)				1 Months Ended					3 Months Ended		12 Months Ended
	Oct. 01, 2019	Sep. 30, 2019	Feb. 13, 2015 USD ($)	Mar. 31, 2017 USD ($)	Nov. 30, 2016 USD ($)	Jan. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Feb. 28, 2015 USD ($)	Sep. 30, 2017 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2019 USD ($) product	Dec. 31, 2017 USD ($)	Dec. 31, 2015 USD ($)	Sep. 20, 2017
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Clinical development cost sharing percentage (in percentage)														50.00%
Proceeds from upfront license agreement payment									$ 12,500,000			$ 12,500,000
Number of products with exclusivity rights | product											33
Marketing rights, term											10 years
Cephalon, Inc.
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront cash (payment) proceeds for license agreement				$ 25,000,000		$ 30,000,000		$ 30,000,000		$ 30,000,000			$ 30,000,000
Licensing agreement, milestone proceeds						$ 15,000,000	$ 15,000,000
Licensing agreement, proceeds from unique billing code					$ 40,000,000
Maximum additional milestone payments			$ 25,000,000	$ 25,000,000
Royalty payments if product is approved, percentage of net sales (in percentage)	30.00%	25.00%	20.00%		25.00%
Royalty revenue, percent of net sales threshold (in percentage)	32.00%
Teva Pharmaceuticals
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront cash (payment) proceeds for license agreement											$ 9,000,000