Income Taxes - Schedule of Components of Income Tax (Benefit) Expense (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Current:
Federal	$ 74,388	$ (875)
Foreign	38,113	32,649	44,481
State	(370)	2,336	2,913
Total current	112,131	34,110	47,394
Deferred:
Federal	(199,162)	(20,622)	22,119
Foreign	5,190	28,054	(6,514)
State	(3,441)	9,013	196
Total deferred	(153,470)	(16,119)	52,612
Income tax (benefit) expense	$ (85,282)	$ 50,555	$ 63,195