Benefit Plans (Detail) - Schedule of Defined Benefits Plan Net Benefit Cost (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Sep. 30, 2010
Interest cost on projected benefit obligation	$ 24	$ 99	$ 25	$ 84	$ 92
Net amortization and deferral of loss	24	96		66	26
Transition obligation	20	59		79	79
Net pension cost included in employee benefit expense	$ 68	$ 254		$ 229	$ 197