Differences between Income Tax Provision and Income Taxes Computed using Applicable U.S. Statutory Federal Tax Rate (Detail) (USD $) In Thousands	12 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009
Income Taxes [Line Items]
Income tax provision (benefit) computed at federal statutory rate	$ 45,736	$ 19,622	$ (79,420)
State income taxes, net of federal benefit	1,848	699	(1,308)
Net operating loss carryback refund		(3,899)
Impairments			25,130
Foreign income taxed at different rates	(1,546)	(1,650)	(1,233)
Dividends	(219)	1,006	1,362
Change in deferred tax asset valuation allowance	(42,608)	(18,423)	55,211
Reduction in uncertain tax positions	(3,719)	(609)	(712)
Other	2,462	508	1,613
Income tax provision (benefit)	$ 1,954	$ (2,746)	$ 643