Capital Lease - Related Party (Detail Textuals) (Aero Metal Products, Inc. (AMP), USD $)	0 Months Ended
Nov. 03, 2009
Aero Metal Products, Inc. (AMP)
Related Party Transaction [Line Items]
Monthly payments	$ 7,500
Interest rate	2.00%

This element represent capital lease transaction monthly rental payments to related party, interest rate.

No definition available.

Name:	svt_CapitalLeaseTransactionMonthlyRentalPaymentsToRelatedPartyInterestRate
Namespace Prefix:	svt_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration