Note 6 - Revenue From Contracts with Customers (Details Textual) - USD ($)	1 Months Ended				3 Months Ended	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2016	Feb. 29, 2016	Sep. 30, 2015	Jun. 30, 2018	Dec. 31, 2019	Dec. 31, 2018
Current and Long-term Prepaid Expenses [Member]
Deferred Sublicense Payments							$ 0
Other Assets [Member]
Deferred Sublicense Payments							$ 807,192
Deferred Sublicense Payments [Member]
Capitalized Contract Cost, Amortization	$ 807,192
Capitalized Contract Cost, Net, Total						$ 0
GSK Inhaled 1 [Member]
Nonrefundable Payment To Be Received				$ 15,000,000
Collaboration Agreement Milestone Payment			$ 3,000,000
Collaboration Agreement Combined Up Front and Milestone Payments			$ 18,000,000
Contract with Customer, Liability, Revenue Recognized						$ 8,100,000
G & W [Member]
Non Refundable Up Front Fee		$ 1,000,000
Unamortized Deferred Revenue Recorded As Revenue					$ 900,000
Unamortized Deferred Sublicense Payments Recorded As Cost Of Sales					$ 100,000