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

Quarterly report pursuant to Section 13 or 15(d)

FAIR VALUE MEASUREMENT (Financial Assets And Financial Liabilities Carried At Fair Value On A Recurring Basis) (Detail)

FAIR VALUE MEASUREMENT (Financial Assets And Financial Liabilities Carried At Fair Value On A Recurring Basis) (Detail) (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]
Available-for-sale securities	$ 307,379us-gaap_AvailableForSaleSecurities	$ 298,310us-gaap_AvailableForSaleSecurities
Fair Value Measurements Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value	307,379	298,310
Fair Value Measurements Recurring [Member] \| U.S. Treasury and Government Sponsored Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	55,246	51,138
Fair Value Measurements Recurring [Member] \| Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	96,264	95,523
Fair Value Measurements Recurring [Member] \| State and Municipal Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	139,838	135,663
Fair Value Measurements Recurring [Member] \| Corporate Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	16,031	15,986
Fair Value Measurements Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value	0	0
Fair Value Measurements Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| U.S. Treasury and Government Sponsored Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value Measurements Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value Measurements Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| State and Municipal Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value Measurements Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| Corporate Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value Measurements Recurring [Member] \| Fair Value Inputs Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value	307,379	298,310
Fair Value Measurements Recurring [Member] \| Fair Value Inputs Level 2 [Member] \| U.S. Treasury and Government Sponsored Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	55,246	51,138
Fair Value Measurements Recurring [Member] \| Fair Value Inputs Level 2 [Member] \| Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	96,264	95,523
Fair Value Measurements Recurring [Member] \| Fair Value Inputs Level 2 [Member] \| State and Municipal Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	139,838	135,663
Fair Value Measurements Recurring [Member] \| Fair Value Inputs Level 2 [Member] \| Corporate Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	16,031	15,986
Fair Value Measurements Recurring [Member] \| Fair Value Inputs Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value	0	0
Fair Value Measurements Recurring [Member] \| Fair Value Inputs Level 3 [Member] \| U.S. Treasury and Government Sponsored Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value Measurements Recurring [Member] \| Fair Value Inputs Level 3 [Member] \| Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value Measurements Recurring [Member] \| Fair Value Inputs Level 3 [Member] \| State and Municipal Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0	0
Fair Value Measurements Recurring [Member] \| Fair Value Inputs Level 3 [Member] \| Corporate Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	$ 0	$ 0