Deposits - Total Deposits (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Banking and Thrift [Abstract]
Percentage Change, Checking, non-interest bearing	10.70%
Percentage Change, Checking, interest bearing	(2.20%)
Percentage Change, Savings accounts	(3.70%)
Percentage Change, Certificates of deposit	11.30%
Percentage change, Total	0.00%
Checking, non-interest bearing	$ 270,816	$ 244,743
Checking, interest bearing	443,144	453,102
Savings accounts	936,837	972,327
Certificates of deposit	196,895	176,907
Total deposits	$ 1,847,692	$ 1,847,079