Income Taxes - Reconciliation of Federal Statutory Tax Rate to Company's Effective Tax Rate (Detail)	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Reconciliation Of Statutory Federal Tax Rate [Line Items]
Federal statutory tax rate	35.00%	35.00%	35.00%
State and local income taxes, net of federal tax benefit	0.20%	1.20%	1.00%
Effect of foreign and Puerto Rico earnings and foreign tax credits	(8.20%)	(7.50%)	(5.60%)
Effect of Research Credits and Domestic Production Activities,	(1.70%)	(2.70%)	(1.70%)
Other, net	(0.70%)	(0.20%)	0.10%
Total	24.60%	25.80%	28.80%