Loans and Allowance for Loan Losses - Summary of Nonperforming and Restructured Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Summary Of Nonperforming And Restructured Assets [Abstract]
Past due 90 days or more and still accruing	$ 1,962	$ 1,841
Nonaccrual	31,798	30,096
Restructured	1,713	15,143
Total nonperforming and restructured loans	35,473	47,080
Other real estate owned and repossessed assets	3,866	8,214
Total nonperforming and restructured assets	$ 39,339	$ 55,294