Securities - Securities Available for Sale (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Amortized cost
Total debt securities	$ 525,343	$ 521,337
Unrealized Gains (Losses)
Accumulated gross unrealized gain, before tax	10,495	2,853
Accumulated gross unrealized loss, before tax	(1,868)	(7,327)
Amortized Cost
Securities available for sale	533,970	516,863
U.S. Gov’t sponsored entities
Amortized cost
Total debt securities	138,235	134,010
Unrealized Gains (Losses)
Accumulated gross unrealized gain, before tax	2,633	254
Accumulated gross unrealized loss, before tax	(141)	(1,570)
Amortized Cost
Securities available for sale	140,727	132,694
State & political subdivisions
Amortized cost
Total debt securities	116,140	134,662
Unrealized Gains (Losses)
Accumulated gross unrealized gain, before tax	3,387	1,942
Accumulated gross unrealized loss, before tax	(73)	(573)
Amortized Cost
Securities available for sale	119,454	136,031
Residential & multi-family mortgage
Amortized cost
Total debt securities	229,925	209,126
Unrealized Gains (Losses)
Accumulated gross unrealized gain, before tax	4,086	500
Accumulated gross unrealized loss, before tax	(947)	(3,573)
Amortized Cost
Securities available for sale	233,064	206,053
Corporate notes & bonds
Amortized cost
Total debt securities	12,352	12,356
Unrealized Gains (Losses)
Accumulated gross unrealized gain, before tax	16	22
Accumulated gross unrealized loss, before tax	(479)	(601)
Amortized Cost
Securities available for sale	11,889	11,777
Pooled SBA
Amortized cost
Total debt securities	27,671	30,163
Unrealized Gains (Losses)
Accumulated gross unrealized gain, before tax	373	135
Accumulated gross unrealized loss, before tax	(168)	(924)
Amortized Cost
Securities available for sale	27,876	29,374
Other
Amortized cost
Total debt securities	1,020	1,020
Unrealized Gains (Losses)
Accumulated gross unrealized gain, before tax	0	0
Accumulated gross unrealized loss, before tax	(60)	(86)
Amortized Cost
Securities available for sale	$ 960	$ 934