Note 7 - Employee Benefit and Savings Plans - Contributions to 401(k) Plan (Details) - USD ($)		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Maximum Matching Contribution per Participant*	[1]	$ 10,600	$ 10,600	$ 10,400
Total Matching Contribution		$ 326,612	$ 277,753	$ 290,388

[1] Due to the annual limit on eligible earnings imposed by the Internal Revenue Code