Commitments - Additional Information (Detail) (USD $)	6 Months Ended
Mar. 31, 2015	Jun. 28, 2011
Commitments and Contingencies Disclosure [Abstract]
Purchase which is not recorded on Company's Balance Sheet	$ 1,200,000
Lease Term	November 2011 through December 2018
Leasehold improvement liability		613,000sofo_LeaseholdImprovementLiability
Unamortized balance of lease	$ 314,000

Amount of the recorded obligation to transfer funds in the future for fixed or minimum amounts or quantities of goods or services at fixed or minimum prices (for example, as in take-or-pay contracts or throughput contracts).

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 440

-SubTopic 10

-Section 50

-Paragraph 6

-URI http://asc.fasb.org/extlink&oid=6394976&loc=d3e25383-109308

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