Activity Related to Restructuring Accruals (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2012	Mar. 31, 2011
Restructuring Cost and Reserve [Line Items]
Beginning Balance		$ 2,525		$ 3,509
Restructuring expense		246		460
Utilization		(1,218)		(2,416)
Ending Balance		1,553		1,553
Facilities and other
Restructuring Cost and Reserve [Line Items]
Beginning Balance		2,525		3,509
Restructuring expense		138		187
Utilization		(1,110)		(2,143)
Ending Balance		1,553		1,553
Workforce-related
Restructuring Cost and Reserve [Line Items]
Beginning Balance	321		293
Restructuring expense	42	108	245	273
Utilization	(243)	(108)	(418)	(273)
Ending Balance	$ 120		$ 120