Restructuring Expenses - Additional Information (Detail) (USD $)	3 Months Ended
	Dec. 31, 2012 Position
Restructuring Cost and Reserve [Line Items]
Restructuring charges, net	$ 2,500,000
Restructuring charges	2,719,000
Number of positions reduced	52
Reversal of severance cost	(253,000)
Facilities charges
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1,600,000
Employee separation
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1,100,000
Reversal of severance cost	$ 200,000