Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Comprehensive income
Net income	$ 10,154	$ 8,292	$ 5,850
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Unrealized holding gain (loss) on investment securities available for sale, net of income taxes of $0, ($2), and ($32), respectively	1	(4)	(63)
Reclassification adjustment for gain on sale of investment securities available for sale included in net income, net of income taxes of $0,( $15) and $0, respectively	0	(30)	0
Change in OTTI on investment securities held to maturity, net of income taxes:
Adjustments related to other factors for which OTTI was previously recognized, net of income taxes of $7, $7, and $7, respectively	12	13	13
Amount reclassified to credit loss for previously recorded market loss, net of income taxes of $49, $4, and $11, respectively	90	9	21
Accretion of OTTI on investment securities held to maturity, net of income taxes of $18, $20, and $27, respectively	35	38	52
Total other comprehensive income, net of income taxes	138	26	23
Total comprehensive income	$ 10,292	$ 8,318	$ 5,873