Quarterly report pursuant to Section 13 or 15(d)

CONSOLIDATED BALANCE SHEETS (Parenthetical)

v2.4.1.9
CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)
In Thousands, except Share data, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Held to maturity debt securities, fair value $ 29,886us-gaap_HeldToMaturitySecuritiesFairValue $ 29,974us-gaap_HeldToMaturitySecuritiesFairValue
Common stock, par value $ 0.001us-gaap_CommonStockParOrStatedValuePerShare $ 0.001us-gaap_CommonStockParOrStatedValuePerShare
Common stock, shares authorized 50,000,000us-gaap_CommonStockSharesAuthorized 50,000,000us-gaap_CommonStockSharesAuthorized
Common stock, shares issued 25,653,610us-gaap_CommonStockSharesIssued 24,801,518us-gaap_CommonStockSharesIssued
Common stock, shares outstanding 25,653,610us-gaap_CommonStockSharesOutstanding 24,801,518us-gaap_CommonStockSharesOutstanding
Series A Preferred Stock [Member]    
Preferred stock, par value $ 0.001us-gaap_PreferredStockParOrStatedValuePerShare
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
$ 0.001us-gaap_PreferredStockParOrStatedValuePerShare
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
Preferred stock, liquidation preference $ 1,000us-gaap_PreferredStockLiquidationPreference
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
$ 1,000us-gaap_PreferredStockLiquidationPreference
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
Preferred stock, authorized 40,000us-gaap_PreferredStockSharesAuthorized
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
40,000us-gaap_PreferredStockSharesAuthorized
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
Preferred stock, shares issued 40,000us-gaap_PreferredStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
40,000us-gaap_PreferredStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
Preferred stock, shares outstanding 40,000us-gaap_PreferredStockSharesOutstanding
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
40,000us-gaap_PreferredStockSharesOutstanding
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
Undesignated Preferred Stock [Member]    
Preferred stock, par value $ 0.001us-gaap_PreferredStockParOrStatedValuePerShare
/ us-gaap_StatementClassOfStockAxis
= sfbs_UndesignatedPreferredStockMember
$ 0.001us-gaap_PreferredStockParOrStatedValuePerShare
/ us-gaap_StatementClassOfStockAxis
= sfbs_UndesignatedPreferredStockMember
Preferred stock, undesignated 960,000sfbs_PreferredStockSharesUndesignated
/ us-gaap_StatementClassOfStockAxis
= sfbs_UndesignatedPreferredStockMember
960,000sfbs_PreferredStockSharesUndesignated
/ us-gaap_StatementClassOfStockAxis
= sfbs_UndesignatedPreferredStockMember
Preferred stock, shares outstanding 1,000,000us-gaap_PreferredStockSharesOutstanding
/ us-gaap_StatementClassOfStockAxis
= sfbs_UndesignatedPreferredStockMember
1,000,000us-gaap_PreferredStockSharesOutstanding
/ us-gaap_StatementClassOfStockAxis
= sfbs_UndesignatedPreferredStockMember