Net Income Per Share Data - Denominator for Computation of Basic and Diluted Net Income Per Share (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Earnings Per Share [Abstract]
Net income available to common shareholders	$ 506	$ 821	$ 2,806	$ 3,474
Basic weighted average shares outstanding	13,220	12,969	13,207	12,956
Dilutive effect of outstanding stock options, non-vested restricted stock, restricted stock units, deferred stock units and performance shares	208	221	208	231
Diluted weighted average shares outstanding	13,428	13,190	13,415	13,187