Segment Information - Reconciliation of Reportable Segment Operating Income (Loss) to Corresponding Consolidated Amounts (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Amortization of acquired intangible assets			$ 26,200	$ 17,700
Restructuring Charges	$ 256	$ 81	685	129
Segment operating income	16,423	12,547	35,427	27,794
Operating Segments
Segment Reporting Information [Line Items]
Segment operating income	23,524	18,592	62,386	45,836
Segment Reconciling Items
Segment Reporting Information [Line Items]
Amortization of acquired intangible assets	6,187	5,080	18,569	14,296
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Other unallocated corporate expenses	$ 658	$ 884	$ 7,705	$ 3,617

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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