Accumulated Other Comprehensive (Loss) Income - Components of Accumulated Other Comprehensive (Loss) Income, Net of Taxes (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (6,920)	$ (6,101)	$ (6,766)
Net Change	(3,035)	(819)	665
Ending balance	(9,955)	(6,920)	(6,101)
Net Unrealized Holding Gains (Losses) on Available-for-Sale Investment Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	8,344	7,306	884
Net Change	(9,816)	1,038	6,422
Ending balance	(1,472)	8,344	7,306
Net Change in Related to Derivative Used for Cash Flow Hedge [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(1,241)	(932)	320
Net Change	(1,241)	(309)	(1,252)
Ending balance		(1,241)	(932)
Net Change Related to Defined Benefit Pension Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(14,023)	(12,475)	(7,970)
Net Change	5,540	(1,548)	(4,505)
Ending balance	$ (8,483)	$ (14,023)	$ (12,475)