Premises and Equipment - Summary of Premises and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Total cost	$ 70,622	$ 65,212
Accumulated depreciation	(24,428)	(23,028)
Net premise and equipment	46,194	42,184
Land [Member]
Property, Plant and Equipment [Line Items]
Total cost	13,323	12,132
Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Total cost	45,466	41,109
Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Total cost	$ 11,833	$ 11,971