Accrued Interest Receivable and Other Assets - Details of Accrued Interest Receivable and Other Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Interest Receivable and Other Assets [Abstract]
Other real estate owned	$ 1,276	$ 955
Accrued interest receivable	7,463	6,086
Accrued income and other receivables	2,725	2,655
Fair market value of derivative financial instruments	1,089	788
Other prepaid expenses	10,880	13,963
Federal Reserve Bank stock, Federal Home Loan Bank stock and other not readily marketable equity securities	8,880	4,487
Net federal deferred tax assets	10,521	10,756
Total accrued interest and other assets	$ 42,834	$ 39,690