Loans and Allowance for Loan Losses - Summary of Nonperforming and Restructured Assets (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Summary Of Nonperforming And Restructured Assets [Abstract]
Past due 90 days or more and still accruing	$ 910	$ 1,179	$ 542
Nonaccrual	17,753	14,390	20,933
Restructured	17,468	17,624	17,792
Total nonperforming and restructured loans	36,131	33,193	39,267
Other real estate owned and repossessed assets	7,590	8,386	9,424
Total nonperforming and restructured assets	$ 43,721	$ 41,579	$ 48,691
Nonperforming and restructured loans to total loans	1.02%	0.98%	1.22%
Nonperforming and restructured assets to total assets	0.69%	0.69%	0.84%