Deposits - Total Deposits (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Banking And Thrift [Abstract]
Percentage change, Checking, non-interest bearing	8.10%
Percentage change, Checking, interest bearing	11.30%
Percentage change, Savings accounts	5.50%
Percentage change, Certificate of deposit	(12.50%)
Percentage change, Total	4.50%
Checking, non-interest bearing	$ 189,362	$ 175,239
Checking, interest bearing	374,826	336,911
Savings accounts	801,677	759,910
Certificates of deposit	186,416	212,943
Total deposits	$ 1,552,281	$ 1,485,003