Government Grants - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Sep. 30, 2012
Government Grants [Line Items]
Unamortized portion of deferred grant revenue recorded in other long-term liabilities	$ 338	$ 334

Unamortized portion of deferred grant revenue recorded in other long-term liabilities.

No definition available.

Name:	sif_UnamortizedPortionOfDeferredGrantRevenueRecordedInOtherLongTermLiabilities
Namespace Prefix:	sif_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant