Income Taxes (Additional Information) (Detail) (USD $)	3 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2013
Business Acquisition [Line Items]
Income taxes associated with uncertain tax position	$ 20,100,000		$ 19,600,000
U.S. federal statutory income tax rate	35.00%
Effective tax rate	(5.70%)	27.90%
Provision (benefit) from income taxes	$ 2,978,000	$ (8,561,000)