Pension and Retirement Plans (Detail) - Fair value of the assets held by the UK pension plan by asset category (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Defined Benefit Plan Disclosure [Line Items]
Plan assets fair value	$ 10,094	$ 9,473
Fair Value Measurements Using Inputs Considered as Level I
Defined Benefit Plan Disclosure [Line Items]
Plan assets fair value	352	452
Fair Value Measurements Using Inputs Considered as Level II
Defined Benefit Plan Disclosure [Line Items]
Plan assets fair value	9,742	9,021
Fair Value Measurements Using Inputs Considered as Level III
Defined Benefit Plan Disclosure [Line Items]
Plan assets fair value	0	0
Cash on deposit
Defined Benefit Plan Disclosure [Line Items]
Plan assets fair value	352	452
Cash on deposit | Fair Value Measurements Using Inputs Considered as Level I
Defined Benefit Plan Disclosure [Line Items]
Plan assets fair value	352	452
Cash on deposit | Fair Value Measurements Using Inputs Considered as Level II
Defined Benefit Plan Disclosure [Line Items]
Plan assets fair value	0	0
Cash on deposit | Fair Value Measurements Using Inputs Considered as Level III
Defined Benefit Plan Disclosure [Line Items]
Plan assets fair value	0	0
Pooled Funds
Defined Benefit Plan Disclosure [Line Items]
Plan assets fair value	9,742	9,021
Pooled Funds | Fair Value Measurements Using Inputs Considered as Level I
Defined Benefit Plan Disclosure [Line Items]
Plan assets fair value	0	0
Pooled Funds | Fair Value Measurements Using Inputs Considered as Level II
Defined Benefit Plan Disclosure [Line Items]
Plan assets fair value	9,742	9,021
Pooled Funds | Fair Value Measurements Using Inputs Considered as Level III
Defined Benefit Plan Disclosure [Line Items]
Plan assets fair value	$ 0	$ 0