Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements - Additional Information (Detail)

v3.3.1.900
Fair Value Measurements - Additional Information (Detail) - USD ($)
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Loans held for sale $ 2,874,000 $ 5,451,000 $ 0
Investment in FRB stock 14,098,000 12,273,000  
Minimum [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Unpaid principal balance of Non-accrual Non-PCI loans reviewed individually for amount of impairment 100,000    
Maximum [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Unpaid principal balance of Non-accrual Non-PCI loans reviewed collectively for amount of impairment 100,000    
Significant Observable Inputs with No Active Market with Identical Characteristics [Member] | Fair Value [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Investment in FHLB 16,385,000 17,580,000  
Investment in FRB stock 14,098,000 12,273,000  
Significant Observable Inputs with No Active Market with Identical Characteristics [Member] | Non-recurring Basis [Member] | Nonperforming Loans Held For Sale [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Loans held for sale 0 0  
Significant Observable Inputs with No Active Market with Identical Characteristics [Member] | Non-recurring Basis [Member] | Small Business Administration Loans Held for Sale [Member]      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Loans held for sale $ 2,900,000 $ 5,500,000