Summary of Accrual Activity Relating to Restructuring and Other Charges (Detail) (USD $) In Thousands	9 Months Ended
	Jun. 30, 2011
Restructuring Cost and Reserve [Line Items]
Balance at September 30, 2010	$ 2,121
Restructuring and other charges, net	5,572
Non-cash adjustment	43
Cash payments	(5,574)
Balance at June 30, 2011	2,162
Personnel
Restructuring Cost and Reserve [Line Items]
Balance at September 30, 2010	1,838
Restructuring and other charges, net	3,854
Non-cash adjustment	208
Cash payments	(4,629)
Balance at June 30, 2011	1,271
Facilities
Restructuring Cost and Reserve [Line Items]
Balance at September 30, 2010	283
Restructuring and other charges, net	1,460
Cash payments	(852)
Balance at June 30, 2011	891
Other
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net	258
Non-cash adjustment	(165)
Cash payments	$ (93)