XML 50 R39.htm IDEA: XBRL DOCUMENT v3.20.2
Note 3 - Fair Value Measurements (Details Textual) - USD ($)
$ in Thousands
6 Months Ended 12 Months Ended
Sep. 30, 2020
Sep. 30, 2019
Mar. 31, 2020
Aug. 12, 2019
Money Market Funds, at Carrying Value $ 222,806   $ 66,735  
Proceeds from Convertible Debt $ 145,935 $ 84,995    
The Notes [Member]        
Debt Instrument, Interest Rate, Stated Percentage 1.375% 1.375%    
Senior Notes [Member] | The Notes [Member]        
Proceeds from Convertible Debt     $ 172,500  
Debt Instrument, Interest Rate, Stated Percentage 1.375%   1.375% 1.375%