ServisFirst Bancshares, Inc. Quarterly report pursuant to Section 13 or 15(d)

FAIR VALUE MEASUREMENT (Carrying Amount And Estimated Fair Value Of Financial Instruments) (Detail) (Fair Value Measurements Nonrecurring [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	$ 39,649sfbs_ImpairedLoansFairValueDisclosure	$ 21,631sfbs_ImpairedLoansFairValueDisclosure
Other real estate owned and repossessed assets	8,638us-gaap_OtherAssetsFairValueDisclosure	6,840us-gaap_OtherAssetsFairValueDisclosure
Total assets at fair value	45,287us-gaap_AssetsFairValueDisclosure	28,471us-gaap_AssetsFairValueDisclosure
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Other real estate owned and repossessed assets	0	0
Total assets at fair value	0	0
Fair Value Inputs Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Other real estate owned and repossessed assets	0	0
Total assets at fair value	0	0
Fair Value Inputs Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	39,649	21,631
Other real estate owned and repossessed assets	8,638	6,840
Total assets at fair value	$ 45,287	$ 28,471