Components of Net Pension Cost (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 148	$ 29	$ 448	$ 86
Interest cost	248	192	745	577
Amortization of losses	116	116	347	348
Expected return on assets	(234)	(188)	(704)	(563)
Net periodic pension cost	$ 278	$ 149	$ 836	$ 448