Earnings per Share - Reconciliation of Shares Outstanding for Basic and Diluted Earnings per Share (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Weighted average shares issued net of Treasury shares	25,823	17,146	22,010	16,954
Less:Unallocated ESOP shares	(340)	(374)	(348)	(382)
Unallocated incentive award shares and shares held by deferred compensation plan	(48)	(39)	(38)	(50)
Average basic shares outstanding	25,435	16,733	21,624	16,522
Add: Effect of dilutive securities:
Stock options	434	200	347	204
Shares held by deferred compensation plan	20	20	19	20
Average diluted shares outstanding	25,889	16,953	21,990	16,746