Segment Information Reconciliation of Reportable Segment Assets to Corresponding Consolidated Amounts (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Sep. 30, 2012
Segment Reporting, Asset Reconciling Item [Line Items]
Investments in cash, cash equivalents, restricted cash and marketable securities	$ 150,726	$ 200,994
Deferred tax assets	112,793	120,157
Investments in joint ventures	23,582	31,428
Other unallocated corporate net assets	15,708	6,932
Total assets	720,430	741,960
Operating Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 417,621	$ 382,449