Net Income Per Common Share: Schedule of Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Earnings Per Share, Basic [Abstract]
Numerator – net income	$ 6,306	$ 5,738	$ 20,476	$ 16,550
Denominator – weighted average common shares outstanding (in shares)	8,156,831	8,279,436	8,203,255	8,324,371
Basic net income per common share (in dollars per share)	$ 0.77	$ 0.69	$ 2.50	$ 1.99
Earnings Per Share, Diluted [Abstract]
Effect of dilutive stock options (in shares)	57,144	70,423	75,824	82,606
Weighted average common shares and common stock equivalents (in shares)	8,213,975	8,349,859	8,279,079	8,406,977
Diluted net income per common share (in dollars per share)	$ 0.77	$ 0.69	$ 2.47	$ 1.97
Stock Options
Earnings Per Share, Diluted [Abstract]
Antidilutive securities excluded from computation of earnings per share (in shares)	256,503	201,150	203,823	205,221