Segment Information - Reconciliation of Reportable Segment Assets to Corresponding Consolidated Amounts (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Sep. 30, 2018
Segment Reporting Information [Line Items]
Cash, cash equivalents and marketable securities	$ 138,308	$ 251,226
Deferred tax assets	23,287	43,798
Assets	1,496,731	1,095,257
Discontinued Operations, Held-for-sale
Segment Reporting Information [Line Items]
Assets held for sale	130,301	125,200
Operating Segments
Segment Reporting Information [Line Items]
Assets	$ 1,204,835	$ 675,033

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.

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Amount classified as assets attributable to disposal group held for sale or disposed of.

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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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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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