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
	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Net income available to common shareholders	$ 2,300	$ 2,653
Basic weighted average shares outstanding	13,200	12,966
Dilutive effect of outstanding stock options, non-vested restricted stock, restricted stock units, deferred stock units and performance shares	246	220
Diluted weighted average shares outstanding	13,446	13,186