Fair Value Measurements - Schedule of Quantitative Information of Assets Measured at Fair Value on Nonrecurring Basis (Detail) (Fair Value, Measurements, Nonrecurring [Member], USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Impaired Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Estimate	$ 11,359	$ 9,856
Mortgage Servicing Rights [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Estimate	228	225
Level III [Member] | Impaired Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Estimate	11,359	9,856
Level III [Member] | Mortgage Servicing Rights [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Estimate	228	225
Level III [Member] | Discounted Cash Flow [Member] | Impaired Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Estimate	10,695	8,663
Level III [Member] | Discounted Cash Flow [Member] | Mortgage Servicing Rights [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Estimate	228	225
Level III [Member] | Discounted Cash Flow [Member] | Minimum [Member] | Impaired Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Remaining term	1 month	3 months
Discount rate	4.30%	7.10%
Level III [Member] | Discounted Cash Flow [Member] | Minimum [Member] | Mortgage Servicing Rights [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Remaining term	6 months	12 months
Level III [Member] | Discounted Cash Flow [Member] | Maximum [Member] | Impaired Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Remaining term	28 years	29 years
Discount rate	12.00%	12.00%
Level III [Member] | Discounted Cash Flow [Member] | Maximum [Member] | Mortgage Servicing Rights [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Remaining term	30 years	30 years
Level III [Member] | Discounted Cash Flow [Member] | Weighted Average [Member] | Impaired Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Remaining term	69 months	62 months
Discount rate	6.80%	7.50%
Level III [Member] | Discounted Cash Flow [Member] | Weighted Average [Member] | Mortgage Servicing Rights [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Remaining term		244 months
Discount rate	1.50%	1.50%
Level III [Member] | Appraisal of Collateral [Member] | Impaired Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Estimate	$ 664	$ 1,193
Level III [Member] | Appraisal of Collateral [Member] | Minimum [Member] | Impaired Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Appraisal adjustments	(20.00%)	(20.00%)
Level III [Member] | Appraisal of Collateral [Member] | Maximum [Member] | Impaired Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Appraisal adjustments	(25.00%)	(25.00%)
Level III [Member] | Appraisal of Collateral [Member] | Weighted Average [Member] | Impaired Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Liquidation expense	(10.00%)	(10.00%)