Comprehensive Income (Loss) - Components of Other Comprehensive Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Before Tax Amount
Unrealized holding gains on securities available for sale arising during the period	$ 14,763	$ (4,241)	$ (1,406)
Reclassification adjustment for securities gains included in net income			(2,524)
Net unrealized losses on securities available for sale			(3,930)
Unrealized gains on derivatives	(828)
Unrealized gains on derivatives		9	57
Change in pension liability, net	(64)	29	(27)
Other comprehensive loss	13,871	(4,203)	(3,900)
Tax Benefit (Expense)
Unrealized holding gains on securities available for sale arising during the period	(4,045)	734	503
Reclassification adjustment for securities gains included in net income			884
Net unrealized losses on securities available for sale			1,387
Unrealized gains on derivatives	242
Unrealized gains on derivatives		32	(20)
Change in pension liability, net	18	(9)	11
Other comprehensive loss	(3,785)	757	1,378
Net of Tax Amount
Unrealized holding gains on securities available for sale arising during the period	10,718	(3,507)	(903)
Reclassification adjustment for securities gains included in net income	0	0	(1,640)
Net unrealized losses on securities available for sale			(2,543)
Unrealized gains on derivatives	(586)
Unrealized gains on derivatives		41	37
Change in pension liability, net	(46)	20	(16)
Other comprehensive loss	$ 10,086	$ (3,446)	$ (2,522)