Fair Value - Quantitative Information about Significant Unobservable Inputs Used in Fair Value Measurements (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount for type of property, age of appraisal and current status	8.07%	11.00%
Commercial Loan [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 11,218	$ 13,332
Valuation Techniques	Fair value of collateral
Commercial Real Estate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 15,064	$ 11,857
Valuation Techniques	Fair value of collateral
Minimum [Member] | Commercial Loan [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount for type of property, age of appraisal and current status	0.00%	0.00%
Minimum [Member] | Commercial Real Estate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount for type of property, age of appraisal and current status	10.00%	0.00%
Maximum [Member] | Commercial Loan [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount for type of property, age of appraisal and current status	98.00%	86.00%
Maximum [Member] | Commercial Real Estate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount for type of property, age of appraisal and current status	51.00%	61.00%
Weighted Average [Member] | Commercial Loan [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount for type of property, age of appraisal and current status	47.00%	28.00%
Weighted Average [Member] | Commercial Real Estate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount for type of property, age of appraisal and current status	35.00%	33.00%
Pooled Trust Preferred Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 6,720	$ 7,900
Valuation Techniques	Discounted cash flow
Pooled Trust Preferred Securities [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Additional asset defaults	3.30%	4.10%
Expected asset recoveries	0.00%	0.00%
Pooled Trust Preferred Securities [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Additional asset defaults	4.40%	11.50%
Expected asset recoveries	9.80%	11.50%
Pooled Trust Preferred Securities [Member] | Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Additional asset defaults	4.10%	8.10%
Expected asset recoveries	2.70%	3.10%
Commercial Real Estate Foreclosed Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 1,263	$ 2,526
Valuation Techniques	Fair value of collateral
Commercial Real Estate Foreclosed Assets [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount for type of property, age of appraisal and current status	0.00%	3.00%
Commercial Real Estate Foreclosed Assets [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount for type of property, age of appraisal and current status	58.00%	80.00%
Commercial Real Estate Foreclosed Assets [Member] | Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount for type of property, age of appraisal and current status	23.00%	26.00%
Residential Foreclosed Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 296	$ 203
Valuation Techniques	Fair value of collateral
Residential Foreclosed Assets [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount for type of property, age of appraisal and current status	7.00%	7.00%
Residential Foreclosed Assets [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount for type of property, age of appraisal and current status	47.00%	53.00%
Residential Foreclosed Assets [Member] | Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount for type of property, age of appraisal and current status	31.00%	29.00%