Condensed Financial Information - Parent Company Only - Schedule of Condensed Balance Sheet (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Assets:
Cash and due from banks	$ 50,571	$ 61,573
Interest-earning deposits with other banks	74,557	47,847
Cash and cash equivalents	125,128	109,420	$ 75,409	$ 57,825
Investments in subsidiaries, at equity in net assets:
Other assets	680	322
Total assets	5,380,924	4,984,347
Liabilities:
Subordinated notes	94,818	94,574
Other liabilities	44,514	44,609
Total liabilities	4,705,802	4,360,214
Shareholders' equity:	675,122	624,133	603,374	505,209
Total liabilities and shareholders’ equity	5,380,924	4,984,347
Parent Company [Member]
Assets:
Cash and due from banks	82,673	78,897
Interest-earning deposits with other banks	177	145
Cash and cash equivalents	82,850	79,042	$ 73,756	$ 1,980
Investments in securities	1,004	924
Investments in subsidiaries, at equity in net assets:
Bank	685,387	638,500
Non-banks	0	0
Other assets	18,355	18,340
Total assets	787,596	736,806
Liabilities:
Dividends payable	5,865	5,863
Subordinated notes	94,818	94,574
Other liabilities	11,791	12,236
Total liabilities	112,474	112,673
Shareholders' equity:	675,122	624,133
Total liabilities and shareholders’ equity	$ 787,596	$ 736,806