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, 2016					6,943,868
Balance at beginning of period at Sep. 30, 2016		$ 96,834			$ 9,961		$ (661)	$ 87,709	$ (175)	[1]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		6,275						6,275
Other comprehensive income (loss)		(3)							(3)
Exercise of stock warrant (in shares)					370,899
Exercise of stock warrant		$ 2,496			$ 2,496
Exercise of stock options (in shares)		30,710			30,710
Exercise of stock options		$ 193			$ 193
Common stock dividends ($0.20 and $0.24 per share, respectively)		(1,434)						(1,434)
Earned ESOP shares, net of income taxes		274			$ 142		132
Stock option compensation expense				$ 194		$ 194
Balance at end of period (in shares) at Mar. 31, 2017					7,345,477
Balance at end of period at Mar. 31, 2017		104,829			$ 12,986		(529)	92,550	(178)	[1]
Balance at beginning of period at Dec. 31, 2016	[1]								(189)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		3,128
Other comprehensive income (loss)		11
Balance at end of period (in shares) at Mar. 31, 2017					7,345,477
Balance at end of period at Mar. 31, 2017		104,829			$ 12,986		(529)	92,550	(178)	[1]
Balance at beginning of period (in shares) at Sep. 30, 2017					7,361,077
Balance at beginning of period at Sep. 30, 2017		111,000	[2]		$ 13,286		(397)	98,235	(124)	[1]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		7,883						7,883
Other comprehensive income (loss)		$ (8)							(8)
Exercise of stock options (in shares)		29,150			29,150
Exercise of stock options		$ 234			$ 234
Common stock dividends ($0.20 and $0.24 per share, respectively)		(1,769)						(1,769)
Earned ESOP shares, net of income taxes		416			$ 284		132
Stock option compensation expense				$ 87		$ 87
Balance at end of period (in shares) at Mar. 31, 2018					7,390,227
Balance at end of period at Mar. 31, 2018		117,843			$ 13,891		(265)	104,349	(132)	[1]
Balance at beginning of period at Dec. 31, 2017	[1]								(136)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		4,269
Other comprehensive income (loss)		4
Balance at end of period (in shares) at Mar. 31, 2018					7,390,227
Balance at end of period at Mar. 31, 2018		$ 117,843			$ 13,891		$ (265)	$ 104,349	$ (132)	[1]

[1] All amounts are net of income taxes.

[2] Derived from audited consolidated financial statements.