Summary of Significant Accounting Policies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014 Office	Dec. 31, 2013
Summary Of Significant Accounting Policies [Line Items]
Number of banking offices	16
Number of loan production offices	53
Valuation allowance	$ 17.0	$ 17.3
Single Family Residential Loans
Summary Of Significant Accounting Policies [Line Items]
Percentage of residential loans	42.40%
Single Family Residential Mortgage
Summary Of Significant Accounting Policies [Line Items]
Percentage of residential loans	6.00%