XML 40 R32.htm IDEA: XBRL DOCUMENT v3.10.0.1
Note 10 - Subsequent Events (Details Textual) - $ / shares
3 Months Ended 6 Months Ended
Oct. 17, 2018
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Common Stock, Dividends, Per Share, Declared   $ 1 $ 1 $ 2 $ 2
Subsequent Event [Member]          
Common Stock, Dividends, Per Share, Declared $ 1        
Subsequent Event [Member] | Common Stock [Member]          
Dividends Payable, Date to be Paid Nov. 30, 2018        
Dividends Payable, Date of Record Oct. 29, 2018