Component of Property and Equipment and their Estimated Useful Lives (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Sep. 30, 2015
Property, Plant and Equipment [Line Items]
Property and equipment	$ 178,356	$ 179,631
Less: accumulated depreciation	108,669	111,508
Property and equipment, net	$ 69,687	$ 68,123