Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total		Stock Options	Number of Shares	Number of Shares Stock Options	Unearned Shares Issued to ESOP	Retained Earnings	Accumulated Other Comprehensive Loss
Balance at beginning of period (in shares) at Sep. 30, 2018				7,401,177
Balance at beginning of period at Sep. 30, 2018	$ 124,657			$ 14,394		$ (133)	$ 110,525	$ (129)	[1]
Balance at beginning of period (in shares) at Sep. 30, 2018				7,401,177
Balance at beginning of period at Sep. 30, 2018	124,657			$ 14,394		(133)	110,525	(129)	[1]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	5,615						5,615
Other comprehensive income (loss)	$ (79)							(79)
Exercise of stock options (in shares)	7,400			7,400
Exercise of stock options	$ 71			$ 71
Common stock dividends	(1,911)						(1,911)
Earned ESOP shares, net of income taxes	232			$ 166		66
Stock option compensation expense			$ 53		$ 53
Common stock issued for business combination (in shares)				904,826
Common stock issued for business combination	28,267			$ 28,267		0
Balance at end of period (in shares) at Dec. 31, 2018				8,313,403
Balance at end of period at Dec. 31, 2018	156,905			$ 42,951		(67)	114,166	(145)	[1]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of Accounting Standards Update (ASU) 2016-01							(63)	63
Adoption of Accounting Standards Update (ASU) 2016-01 | Accounting Standards Update 2016-01							(63)
Balance at beginning of period (in shares) at Sep. 30, 2019				8,329,419
Balance at beginning of period at Sep. 30, 2019	171,067	[2]		$ 43,030		0	127,987	50	[1]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	6,652						6,652
Other comprehensive income (loss)	$ (196)							(196)
Exercise of stock options (in shares)	16,975			16,975
Exercise of stock options	$ 170			$ 170
Common stock dividends	(2,086)						(2,086)
Stock option compensation expense			$ 46		$ 46
Balance at end of period (in shares) at Dec. 31, 2019				8,346,394
Balance at end of period at Dec. 31, 2019	$ 175,653			$ 43,246		$ 0	$ 132,553	$ (146)	[1]

[1] All amounts are net of income taxes.

[2] Derived from audited consolidated financial statements.