Other Assets - Summary of Other Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred tax asset, net	$ 26,266	$ 21,697
Investment in low income housing tax credit funds	17,095	16,854
Prepaid expense	4,411	4,111
Tax refund receivable	4,754	4,754
Capital trusts	1,709	1,706
Software	883	1,126
Life insurance proceeds receivable		2,242
Miscellaneous other assets	1,156	2,561
Total other assets	$ 56,274	$ 55,051