Derivatives - Summary Information Regarding Derivatives (Detail) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Customer Interest Rate Swaps [Member]
Derivative [Line Items]
Notional Amount	$ 34,033,000	$ 17,279,000
Average Maturity (Years)	12 years 7 months 6 days	5 years 8 months 12 days
Weighted Average Rate Fixed	4.29%	3.84%
Weighted Average Variable Rate, description	1 Mo Libor + 2.11
Weighted Average Variable Rate	2.11%	2.21%
Fair Value	$ 517,000	$ 37,000
3rd Party Interest Rate Swaps [Member]
Derivative [Line Items]
Notional Amount	$ 34,033,000	$ 17,279,000
Average Maturity (Years)	12 years 7 months 6 days	5 years 8 months 12 days
Weighted Average Rate Fixed	4.29%	3.84%
Weighted Average Variable Rate, description	1 Mo Libor + 2.11
Weighted Average Variable Rate	2.11%	2.21%
Fair Value	$ (517,000)	$ (37,000)