Employee Benefit Plan (Detail) (Pension Plans, Defined Benefit, USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Pension Plans, Defined Benefit
Components of net periodic benefit cost:
Service cost
Interest cost	620	714
Expected return on plan assets	(948)	(941)
Net amortization	664	688
Net periodic benefit cost	$ 336	$ 461