Income Taxes (Additional Information) (Detail) - USD ($)	3 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Sep. 30, 2015
Business Acquisition [Line Items]
Income taxes associated with uncertain tax position	$ 22,600,000		$ 22,200,000
U.S. federal statutory income tax rate	35.00%
Effective tax rate	(180.70%)	(13.00%)
Provision for income taxes	$ 7,767,000	$ 5,814,000
Unrecognized Tax Benefits Expected To Be Resolved With In A Year	$ 0