Retirement Plan - Additional Information (Detail) (Profit Sharing Plan 401(K))	12 Months Ended
Sep. 30, 2012
Profit Sharing Plan 401(K)
Defined Benefit Plan Disclosure [Line Items]
Employer's matching contribution in percent	25.00%
Employer's contribution as percentage of employee compensation	6.00%

Maximum percentage of employee gross pay, by the terms of the plan, that the employer may contribute to a defined contribution plan.

No definition available.

Name:	us-gaap_DefinedContributionPlanMaximumAnnualContributionPerEmployeePercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration