Fair Value Measurements - Financial Assets and Financial Liabilities Measured at Fair Value (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available for sale	$ 19,804	$ 43,836
Items Measured on a Recurring Basis [Member] | U.S. Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available for sale	19,804	35,289
Items Measured on a Recurring Basis [Member] | Equity Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available for sale		8,547
Items Measured on a Non-Recurring Basis [Member] | Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	4,664	4,345
Items Measured on a Non-Recurring Basis [Member] | Loans Measured for Impairment Based on the Fair Value of Underlying Collateral [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	11,675	18,902
Level 1 Inputs [Member] | Items Measured on a Recurring Basis [Member] | Equity Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available for sale		8,547
Level 2 Inputs [Member] | Items Measured on a Recurring Basis [Member] | U.S. Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available for sale	19,804	35,289
Level 3 Inputs [Member] | Items Measured on a Non-Recurring Basis [Member] | Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	4,664	4,345
Level 3 Inputs [Member] | Items Measured on a Non-Recurring Basis [Member] | Loans Measured for Impairment Based on the Fair Value of Underlying Collateral [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	$ 11,675	$ 18,902