Accumulated Other Comprehensive Income - Activity in Accumulated Other Comprehensive Income (Loss), Net of Tax (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	$ (849)	$ 1,726	$ 927
Other comprehensive (loss) income before reclassification	(6,703)	(3,150)	400
Other comprehensive (loss) income	(5,522)	(2,575)	799
Ending balance	(6,371)	(849)	1,726
Reclassification Out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income	1,181	575	398
Securities Available for Sale [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	624	2,924	1,828
Other comprehensive (loss) income before reclassification	(6,684)	(2,612)	892
Other comprehensive (loss) income	(5,952)	(2,300)	1,096
Ending balance	(5,328)	624	2,924
Securities Available for Sale [Member] | Reclassification Out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income	732	312	204
Defined Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(1,473)	(1,198)	(901)
Other comprehensive (loss) income before reclassification	(20)	(539)	(491)
Other comprehensive (loss) income	430	(275)	(297)
Ending balance	(1,043)	(1,473)	(1,198)
Defined Benefit Plans [Member] | Reclassification Out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income	$ 450	$ 264	$ 194