Restructuring and Other Charges Activity Related to Restructuring Accruals (Detail) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Restructuring Reserve [Roll Forward]
Beginning Balance	$ 5,939	$ 2,073
Expenses	975	1,475
Payments	(3,687)	(1,894)
Ending Balance	$ 3,227	1,654
Facilities and other contract termination costs
Restructuring Reserve [Roll Forward]
Beginning Balance		433
Expenses		(135)
Payments		(298)
Ending Balance		0
Workforce-related termination benefits
Restructuring Reserve [Roll Forward]
Beginning Balance		1,640
Expenses		1,610
Payments		(1,596)
Ending Balance		$ 1,654