Net Income (Loss) Per Share Data - Denominator for Computation of Basic and Diluted Net Income (Loss) Per Share (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share [Abstract]
Net income (loss) available to common shareholders	$ 1,534	$ 506	$ (22)	$ 2,806
Basic weighted average shares outstanding	13,102	13,220	13,078	13,207
Dilutive effect of outstanding stock options, non-vested restricted stock, restricted stock units, deferred stock units and performance shares	363	208		208
Diluted weighted average shares outstanding	13,465	13,428	13,078	13,415