Segment Information - Reconciliation of Reportable Segment Operating Income (Loss) to Corresponding Consolidated Amounts (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Amortization of acquired intangible assets	$ 2,754	$ 1,917	$ 8,056	$ 5,743
Restructuring and other charges	996	358	9,807	3,711
Other unallocated corporate expenses	139	61	3,464	520
Operating income (loss)	8,494	10,170	(6,165)	6,743
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating income (loss)	$ 12,383	$ 12,506	$ 15,162	$ 16,717