Segment Information Reconciliation of Reportable Segment Assets to Corresponding Consolidated Amounts (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013
Segment Reporting, Asset Reconciling Item [Line Items]
Investments in cash, cash equivalents, restricted cash and marketable securities	$ 175,667	$ 173,539
Deferred tax assets	114,533	115,985
Investments in joint ventures	25,336	25,687
Other unallocated corporate net assets	5,717	2,032
Total assets	729,669	736,763
Operating Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 408,416	$ 419,520