Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended	9 Months Ended
Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Sep. 30, 2014
Income Tax Disclosure [Abstract]
Accruals of interest and penalties	$ 0		$ 0		$ 0
Recognized interest or penalties	$ 0	$ 0	$ 0	$ 0

The amount of estimated penalties and interest accrued as of the balance sheet date arising from income tax examinations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32718-109319

Name:	us-gaap_IncomeTaxExaminationPenaltiesAndInterestAccrued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant