Other Assets - Summary of Other Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred tax asset, net	$ 21,697	$ 36,199
Prepaid expense	4,111	3,045
Software	1,126	2,039
Advanced compensation	16	249
Capital Trusts	1,706	1,702
Investment in Low Housing Tax Credit Funds	16,854	18,465
Life insurance proceeds receivable	2,242	2,120
Prepaid Taxes	4,754	6,460
Premises held for sale		2,896
Miscellaneous other assets	2,545	1,568
Total other assets	$ 55,051	$ 74,743