Note 13 - Earnings Per Common Share - Summary of Earnings Per Share Calculation (Details) - USD ($)	3 Months Ended									12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Income (Loss) available to common stockholders	$ 510,262				$ (313,706)					$ 1,408,396	$ 4,632,848	$ (122,377)
Shares denominator (in shares)	2,888,502				2,853,107					2,874,926	1,943,625	1,638,215
Basic (in dollars per share)	$ 0.18	$ 0.20	$ 0.33	$ 0.07	$ (0.11)	$ 1.81	$ (0.01)	$ (0.28)	$ (0.03)	$ 0.49	$ 2.38	$ (0.07)
Options and warrants under convertible note (in shares)	367,510				48,477					194,151	16,496
(in shares)	3,256,012				2,901,584					3,069,077	1,960,121	1,638,215
Income (Loss) available to common stockholders	$ 510,262				$ (313,706)					$ 1,408,396	$ 4,632,848	$ (122,377)
Diluted (in dollars per share)	$ 0.16	$ 0.18	$ 0.31	$ 0.07	$ (0.11)	$ 1.77	$ (0.01)	$ (0.28)	$ (0.03)	$ 0.46	$ 2.36	$ (0.07)