Note 10 - Stock Repurchase Program - Schedule of Stock Repurchase Program (Details) - Common Stock [Member] - USD ($)	1 Months Ended			3 Months Ended
	Sep. 30, 2020	Aug. 31, 2020	Jul. 31, 2020	Sep. 30, 2020
Total Shares Purchased (in shares)				1,806
Average price per Share (in dollars per share)	$ 50.62			$ 50.62
Max Dollar Amount of Remaining Shares	$ 3,762,040	$ 3,853,459	$ 3,853,459	$ 3,762,040
Total number of shares purchased during the period [Member]
Total Shares Purchased (in shares)	1,806			1,806
Total number of shares purchased under the Repurchase Program [Member]
Total Shares Purchased (in shares)	1,806			1,806