Income Taxes - Schedule of Income Taxes from Continuing Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Current provision:
U.S. Federal	$ 2,125	$ 6,550	$ 6,065
U.S. State	(72)	250	106
International	54	(98)	30
Total current provision	2,107	6,702	6,201
Deferred provision (benefit):
U.S. Federal	1,085	169	58
U.S. State	(85)	(43)	35
International		135
Total deferred provision (benefit)	1,000	261	93
Income tax provision	$ 3,107	$ 6,963	$ 6,294