Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Accounting Policies [Abstract]
Foreign Currency Transaction Gain (Loss), before Tax	$ (1,900)	$ 500	$ (1,200)
Cash equivalents	100	11,600
Concentration Risk [Line Items]
Increase in non-current deferred tax liabilities	2,913	3,495
New Accounting Pronouncement, Early Adoption, Effect | Accounting Standards Update 2015-17
Concentration Risk [Line Items]
Decrease in current deferred tax assets	17,600	(17,600)
Increase in non-current deferred tax assets	16,700	70,500
Decrease in current deferred tax liabilities	1,300	(1,300)
Increase in non-current deferred tax liabilities	300	$ 3,200
Contact Co., Ltd
Concentration Risk [Line Items]
Measurement period adjustment	(1,100)
Wells Fargo Bank, N.A. | Line of Credit | Revolving Credit Facility
Concentration Risk [Line Items]
Deferred financing costs	$ 700
Top Ten Largest Customers
Concentration Risk [Line Items]
Percentage of concentration risk by customer	34.00%	38.00%	37.00%
Property, Plant and Equipment
Concentration Risk [Line Items]
Capitalized software costs	$ 3,700	$ 0