Income Taxes - Schedule of Significant Portions of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Allowance for loan losses	$ 4,107	$ 3,501
Reserve for repurchased loans	112	55
Reserve for uncollected interest	212	119
Incentive compensation	1,397	1,302
Deferred compensation	591	529
Other reserves	2,737	334
Stock plans	1,270	950
ESOP	178	142
Purchase accounting adjustments	8,475	16,142
Net operating loss carryforward related to acquisition	39,519	44,436
Other real estate owned	0	90
Unrealized loss on securities	826	1,225
Unrealized loss on properties available-for-sale	1,438	1,266
Federal and state alternative minimum tax	4,746	1,410
Total gross deferred tax assets	65,608	71,501
Deferred tax liabilities:
Investments, discount accretion	(380)	(232)
Deferred loan and commitment costs, net	(2,379)	(1,478)
Premises and equipment, differences in depreciation	(7,340)	(4,350)
Undistributed REIT income	(4,735)	(1,730)
Other	(707)	(334)
Total gross deferred tax liabilities	(15,541)	(8,124)
Net deferred tax assets	$ 50,067	$ 63,377