Restructuring Charges - Restructuring Accrual Activities (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Restructuring Cost and Reserve [Line Items]
Beginning Balance	$ 416	$ 192	$ 980
Accrual/(reversal) during the year	(22)	476
Cash payments	(394)	(252)	(788)
Ending Balance		416	192
Employee Severance and Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	399	10	730
Accrual/(reversal) during the year	(20)	534
Cash payments	(379)	(145)	(720)
Ending Balance		399	10
Facility-Related Costs [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	17	182	250
Accrual/(reversal) during the year	(2)	(58)
Cash payments	(15)	(107)	(68)
Ending Balance		$ 17	$ 182