Pension and Retirement Plans (Detail) - Accrued benefit liability - USD ($) $ in Thousands	Sep. 30, 2015	Sep. 30, 2014
Pension and Other Postretirement Defined Benefit Plans, Liabilities [Abstract]
Current accrued benefit liability	$ 675	$ 658
Non-current accrued benefit liability	10,009	10,440
Total accrued benefit liability	$ 10,684	$ 11,098