Earnings per Share - Reconciles Shares Outstanding for Basic and Diluted Earnings Per Share (Detail) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Earnings Per Share [Abstract]
Weighted average shares issued net of Treasury shares	17,258	17,649	17,327	17,740
Less: Unallocated ESOP shares	(416)	(450)	(420)	(455)
Unallocated incentive award shares and shares held by deferred compensation plan	(102)	(94)	(95)	(91)
Average basic shares outstanding	16,740	17,105	16,812	17,194
Average basic shares outstanding	16,740	17,105	16,812	17,194
Add: Effect of dilutive securities:
Stock options	61		109
Shares held by deferred compensation plan	21	39	25	39
Average diluted shares outstanding	16,822	17,144	16,946	17,233