Net Income Per Common Share: Schedule of Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
		Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share, Basic [Abstract]
Numerator – net income		$ 5,615	$ 3,614
Denominator – weighted average common shares outstanding (in shares)		8,293,212	7,312,531
Basic net income per common share (in dollars per share)		$ 0.68	$ 0.49
Earnings Per Share, Diluted [Abstract]
Effect of dilutive stock options (in shares)	[1]	164,491	195,638
Weighted average common shares and common stock equivalents (in shares)		8,457,703	7,508,169
Diluted net income per common share (in dollars per share)		$ 0.66	$ 0.48
Stock Options
Earnings Per Share, Diluted [Abstract]
Antidilutive securities excluded from computation of earnings per share (in shares)		102,850	14,651

[1] For the three months ended December 31, 2017, average options to purchase 14,651 shares of common stock were outstanding but not included in the computation of diluted net income per share because their effect would have been anti-dilutive.