Fair Value Measurements and Disclosures - Summary of Assets Measured at Fair Value on Nonrecurring Basis (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]    
Other real estate and repossessed assets $ 1,380 $ 845
Impaired loans 4,865 3,371
Doubtful [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Impaired loans 4,865 3,371
Level 3 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other real estate and repossessed assets 1,380 845
Level 3 [Member] | Doubtful [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Impaired loans $ 4,865 $ 3,371