Income Taxes - Additional Information (Detail) (USD $)	1 Months Ended	9 Months Ended		12 Months Ended
	Sep. 13, 2013	Sep. 30, 2013	Sep. 30, 2012 Tax Year 2006	Sep. 30, 2014 Unrecognized tax benefits Maximum
Income Tax Contingency
Reduction in noncurrent deferred tax assets	$ (2,100,000)
Estimated unrecognized tax benefits, decrease as a result of tax position taken in prior years		4,336,000		1,828,000
Unrecognized tax benefits that would impact effective tax rate		5,736,000
Refund of federal tax and interest			$ 1,626,000