Annual report pursuant to Section 13 and 15(d)

REGULATORY MATTERS (The Company's And Bank's Actual Capital Amounts And Ratios) (Detail)

v2.4.1.9
REGULATORY MATTERS (The Company's And Bank's Actual Capital Amounts And Ratios) (Detail) (USD $)
Dec. 31, 2014
Dec. 31, 2013
Servisfirst Bank [Member]    
Total Capital to Risk Weighted Assets, Actual Amount $ 397,748us-gaap_Capital
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
$ 341,256us-gaap_Capital
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
Total Capital to Risk Weighted Assets, Actual Ratio 11.62%us-gaap_CapitalToRiskWeightedAssets
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
11.64%us-gaap_CapitalToRiskWeightedAssets
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
Total Capital to Risk Weighted Assets, For Capital Adequacy Purposes, Amount 273,939us-gaap_CapitalRequiredForCapitalAdequacy
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
234,601us-gaap_CapitalRequiredForCapitalAdequacy
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
Total Capital to Risk Weighted Assets, For Capital Adequacy Purposes, Ratio 8.00%us-gaap_CapitalRequiredForCapitalAdequacyToRiskWeightedAssets
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
8.00%us-gaap_CapitalRequiredForCapitalAdequacyToRiskWeightedAssets
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
Total Capital to Risk Weighted Assets, To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount 342,424us-gaap_CapitalRequiredToBeWellCapitalized
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
293,252us-gaap_CapitalRequiredToBeWellCapitalized
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
Total Capital to Risk Weighted Assets, To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio 10.00%us-gaap_CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
10.00%us-gaap_CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
Tier I Capital to Risk Weighted Assets, Actual Amount 362,119us-gaap_TierOneRiskBasedCapital
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
310,593us-gaap_TierOneRiskBasedCapital
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
Tier I Capital to Risk Weighted Assets, Actual Ratio 10.58%us-gaap_ExcessTierOneRiskBasedCapitalToRiskWeightedAssets
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
10.59%us-gaap_ExcessTierOneRiskBasedCapitalToRiskWeightedAssets
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
Tier I Capital to Risk Weighted Assets, For Capital Adequacy Purposes, Amount 136,970us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacy
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
117,301us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacy
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets 4.00%us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
4.00%us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
Tier I Capital to Risk Weighted Assets, To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount 205,454us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalized
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
175,951us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalized
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
Tier I Capital to Risk Weighted Assets, To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio 6.00%us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
6.00%us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
Tier I Capital to Average Assets, Actual Amount 362,119us-gaap_TierOneLeverageCapital
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
310,593us-gaap_TierOneLeverageCapital
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
Tier I Capital to Average Assets, Actual Ratio 8.92%us-gaap_TierOneLeverageCapitalToAverageAssets
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
8.98%us-gaap_TierOneLeverageCapitalToAverageAssets
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
Tier I Capital to Average Assets, For Capital Adequacy Purposes, Amount 162,375us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacy
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
138,331us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacy
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
Tier I Capital to Average Assets, For Capital Adequacy Purposes, Ratio 4.00%us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
4.00%us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
Tier I Capital to Average Assets, To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount 202,969us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalized
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
172,913us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalized
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
Tier I Capital to Average Assets, To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio 5.00%us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
5.00%us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets
/ sfbs_ServisfirstBankAxis
= sfbs_ServisfirstBankMember
Consolidated Entities [Member]    
Total Capital to Risk Weighted Assets, Actual Amount 458,073us-gaap_Capital
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
343,904us-gaap_Capital
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
Total Capital to Risk Weighted Assets, Actual Ratio 13.38%us-gaap_CapitalToRiskWeightedAssets
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
11.73%us-gaap_CapitalToRiskWeightedAssets
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
Total Capital to Risk Weighted Assets, For Capital Adequacy Purposes, Amount 273,943us-gaap_CapitalRequiredForCapitalAdequacy
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
234,617us-gaap_CapitalRequiredForCapitalAdequacy
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
Total Capital to Risk Weighted Assets, For Capital Adequacy Purposes, Ratio 8.00%us-gaap_CapitalRequiredForCapitalAdequacyToRiskWeightedAssets
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
8.00%us-gaap_CapitalRequiredForCapitalAdequacyToRiskWeightedAssets
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
Tier I Capital to Risk Weighted Assets, Actual Amount 402,471us-gaap_TierOneRiskBasedCapital
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
293,301us-gaap_TierOneRiskBasedCapital
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
Tier I Capital to Risk Weighted Assets, Actual Ratio 11.75%us-gaap_ExcessTierOneRiskBasedCapitalToRiskWeightedAssets
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
10.00%us-gaap_ExcessTierOneRiskBasedCapitalToRiskWeightedAssets
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
Tier I Capital to Risk Weighted Assets, For Capital Adequacy Purposes, Amount 136,972us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacy
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
117,308us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacy
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets 4.00%us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
4.00%us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
Tier I Capital to Average Assets, Actual Amount 402,471us-gaap_TierOneLeverageCapital
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
293,301us-gaap_TierOneLeverageCapital
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
Tier I Capital to Average Assets, Actual Ratio 9.91%us-gaap_TierOneLeverageCapitalToAverageAssets
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
8.48%us-gaap_TierOneLeverageCapitalToAverageAssets
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
Tier I Capital to Average Assets, For Capital Adequacy Purposes, Amount $ 162,377us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacy
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
$ 138,373us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacy
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
Tier I Capital to Average Assets, For Capital Adequacy Purposes, Ratio 4.00%us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember
4.00%us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets
/ dei_LegalEntityAxis
= us-gaap_ConsolidatedEntitiesMember