Income Taxes - Company's Net Deferred Tax Asset Recorded in Other Assets (Detail) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Deferred tax assets:
Allowance for losses	$ 17,096,000	$ 19,073,000
Deferred compensation	3,093,000	3,254,000
Accrued pension liability	5,817,000	5,272,000
Accrued bonus	1,037,000	980,000
Other accrued expenses		879,000
Unfunded status of the supplemental retirement plans	331,000	1,600,000
State taxes	1,390,000	1,297,000
Stock option expense	2,225,000	1,879,000
Nonaccrual interest	1,840,000	1,889,000
Acquisition cost basis	699,000	482,000
OREO write downs	331,000	1,103,000
Total deferred tax assets	33,859,000	37,708,000
Deferred tax liabilities:
Securities income	(986,000)	(1,038,000)
Unrealized gain on securities	(1,767,000)	(3,547,000)
Depreciation	(392,000)	(344,000)
Merger related fixed asset valuations	(379,000)	(379,000)
Securities accretion	(256,000)	(150,000)
Mortgage servicing rights valuation	(2,416,000)	(1,641,000)
Indemnification asset	(87,000)	(840,000)
Prepaid expenses and other	(795,000)	(834,000)
Total deferred tax liability	(7,078,000)	(8,773,000)
Net deferred tax asset	$ 26,781,000	$ 28,935,000