Segment Information - Reconciliation of Reportable Segment Assets to Corresponding Consolidated Amounts (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Sep. 30, 2015
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 684,395	$ 759,654
Cash, cash equivalents and marketable securities	68,287	214,030
Deferred tax assets	4,575	89,959
Assets held for sale	2,895	2,900
Equity method investments	25,071	24,286
Other unallocated corporate net assets	0	500
Operating Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 583,567	$ 427,979