GENERAL (Additional Information) (Details)	6 Months Ended
Jun. 30, 2015
Core Deposit Intangible Asset Amortization Period	7 years

It denotes the term of core deposit intangible amortization period in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days..

No definition available.

Name:	sfbs_CoreDepositIntangibleAssetAmortizationPeriod
Namespace Prefix:	sfbs_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration