Summary of Significant Accounting Policies and Select Balance Sheet Information - Denominator for Computation of Basic and Diluted Income Per Share (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]
Net income from continuing operations available to common shareholders	$ 1,358	$ 3,924	$ 3,051	$ 3,614	$ 2,444	$ 3,674	$ 2,459	$ 3,630	$ 11,947	$ 12,207	$ 14,579
Basic weighted average shares outstanding									13,029	13,632	14,464
Dilutive effect of outstanding stock options, non-vested restricted stock, restricted stock units and performance shares									260	244	267
Diluted weighted average shares outstanding									13,289	13,876	14,731