Segment Information - Reconciliation of Reportable Segment Assets to Corresponding Consolidated Amounts (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Assets	$ 746,771	$ 685,905
Cash, cash equivalents and marketable securities	119,658	91,221
Deferred tax assets	1,460	1,982
Equity method investments	32,628	27,273
Operating Segments
Segment Reporting Information [Line Items]
Assets	592,996	565,452
Segment Reconciling Items
Segment Reporting Information [Line Items]
Equity method investments	32,606	$ 27,250
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Other unallocated corporate net assets	$ 51

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
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Amount of net assets (liabilities).

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Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Sum of investments and unrestricted cash as of the balance sheet date.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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