Premises and Equipment - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Property, Plant and Equipment [Abstract]
Depreciation expense for premises and equipment	$ 1,415,000	$ 1,377,000	$ 2,686,000	$ 2,645,000