Components of Net Pension Cost (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 151	$ 25
Interest cost	249	185
Amortization of losses	115	114
Expected return on assets	(235)	(180)
Net periodic pension cost	$ 280	$ 144