Activity Related to Restructuring Accruals (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Restructuring Cost and Reserve [Line Items]
Beginning Balance	$ 293	$ 3,509	$ 7,661
Restructuring expense	3,275	1,036	2,529
Utilization		(4,252)	(6,681)
Ending Balance		293	3,509
Workforce-related
Restructuring Cost and Reserve [Line Items]
Beginning Balance	293		1,372
Restructuring expense	3,275	726	945
Utilization	(1,470)	(433)	(2,317)
Ending Balance	2,098	293
Facilities and other
Restructuring Cost and Reserve [Line Items]
Beginning Balance		3,509	6,289
Restructuring expense		310	1,584
Utilization		(3,819)	(4,364)
Ending Balance			$ 3,509